1 /* Define control and data flow tables, and regsets.
2 Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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 the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 #ifndef GCC_BASIC_BLOCK_H
23 #define GCC_BASIC_BLOCK_H
28 #include "partition.h"
29 #include "hard-reg-set.h"
35 /* Head of register set linked list. */
36 typedef bitmap_head regset_head;
38 /* A pointer to a regset_head. */
39 typedef bitmap regset;
41 /* Allocate a register set with oballoc. */
42 #define ALLOC_REG_SET(OBSTACK) BITMAP_ALLOC (OBSTACK)
44 /* Do any cleanup needed on a regset when it is no longer used. */
45 #define FREE_REG_SET(REGSET) BITMAP_FREE (REGSET)
47 /* Initialize a new regset. */
48 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, ®_obstack)
50 /* Clear a register set by freeing up the linked list. */
51 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
53 /* Copy a register set to another register set. */
54 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
56 /* Compare two register sets. */
57 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
59 /* `and' a register set with a second register set. */
60 #define AND_REG_SET(TO, FROM) bitmap_and_into (TO, FROM)
62 /* `and' the complement of a register set with a register set. */
63 #define AND_COMPL_REG_SET(TO, FROM) bitmap_and_compl_into (TO, FROM)
65 /* Inclusive or a register set with a second register set. */
66 #define IOR_REG_SET(TO, FROM) bitmap_ior_into (TO, FROM)
68 /* Exclusive or a register set with a second register set. */
69 #define XOR_REG_SET(TO, FROM) bitmap_xor_into (TO, FROM)
71 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2. */
72 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
73 bitmap_ior_and_compl_into (TO, FROM1, FROM2)
75 /* Clear a single register in a register set. */
76 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
78 /* Set a single register in a register set. */
79 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
81 /* Return true if a register is set in a register set. */
82 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
84 /* Copy the hard registers in a register set to the hard register set. */
85 extern void reg_set_to_hard_reg_set (HARD_REG_SET *, bitmap);
86 #define REG_SET_TO_HARD_REG_SET(TO, FROM) \
88 CLEAR_HARD_REG_SET (TO); \
89 reg_set_to_hard_reg_set (&TO, FROM); \
92 typedef bitmap_iterator reg_set_iterator;
94 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
95 register number and executing CODE for all registers that are set. */
96 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, RSI) \
97 EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, RSI)
99 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
100 REGNUM to the register number and executing CODE for all registers that are
101 set in the first regset and not set in the second. */
102 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
103 EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI)
105 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
106 REGNUM to the register number and executing CODE for all registers that are
107 set in both regsets. */
108 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
109 EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI) \
111 /* Type we use to hold basic block counters. Should be at least
112 64bit. Although a counter cannot be negative, we use a signed
113 type, because erroneous negative counts can be generated when the
114 flow graph is manipulated by various optimizations. A signed type
115 makes those easy to detect. */
116 typedef HOST_WIDEST_INT gcov_type;
118 /* Control flow edge information. */
119 struct edge_def GTY(())
121 /* The two blocks at the ends of the edge. */
122 struct basic_block_def *src;
123 struct basic_block_def *dest;
125 /* Instructions queued on the edge. */
126 union edge_def_insns {
127 rtx GTY ((tag ("0"))) r;
128 tree GTY ((tag ("1"))) t;
129 } GTY ((desc ("ir_type ()"))) insns;
131 /* Auxiliary info specific to a pass. */
132 PTR GTY ((skip (""))) aux;
134 /* Location of any goto implicit in the edge, during tree-ssa. */
135 source_locus goto_locus;
137 int flags; /* see EDGE_* below */
138 int probability; /* biased by REG_BR_PROB_BASE */
139 gcov_type count; /* Expected number of executions calculated
142 /* The index number corresponding to this edge in the edge vector
144 unsigned int dest_idx;
147 typedef struct edge_def *edge;
149 DEF_VEC_ALLOC_P(edge,gc);
151 #define EDGE_FALLTHRU 1 /* 'Straight line' flow */
152 #define EDGE_ABNORMAL 2 /* Strange flow, like computed
154 #define EDGE_ABNORMAL_CALL 4 /* Call with abnormal exit
155 like an exception, or sibcall */
156 #define EDGE_EH 8 /* Exception throw */
157 #define EDGE_FAKE 16 /* Not a real edge (profile.c) */
158 #define EDGE_DFS_BACK 32 /* A backwards edge */
159 #define EDGE_CAN_FALLTHRU 64 /* Candidate for straight line
161 #define EDGE_IRREDUCIBLE_LOOP 128 /* Part of irreducible loop. */
162 #define EDGE_SIBCALL 256 /* Edge from sibcall to exit. */
163 #define EDGE_LOOP_EXIT 512 /* Exit of a loop. */
164 #define EDGE_TRUE_VALUE 1024 /* Edge taken when controlling
165 predicate is nonzero. */
166 #define EDGE_FALSE_VALUE 2048 /* Edge taken when controlling
167 predicate is zero. */
168 #define EDGE_EXECUTABLE 4096 /* Edge is executable. Only
169 valid during SSA-CCP. */
170 #define EDGE_CROSSING 8192 /* Edge crosses between hot
171 and cold sections, when we
173 #define EDGE_ALL_FLAGS 16383
175 #define EDGE_COMPLEX (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
177 /* Counter summary from the last set of coverage counts read by
179 extern const struct gcov_ctr_summary *profile_info;
181 /* Declared in cfgloop.h. */
185 /* Declared in tree-flow.h. */
188 /* Declared in tree-flow.h. */
189 struct edge_prediction;
191 /* A basic block is a sequence of instructions with only entry and
192 only one exit. If any one of the instructions are executed, they
193 will all be executed, and in sequence from first to last.
195 There may be COND_EXEC instructions in the basic block. The
196 COND_EXEC *instructions* will be executed -- but if the condition
197 is false the conditionally executed *expressions* will of course
198 not be executed. We don't consider the conditionally executed
199 expression (which might have side-effects) to be in a separate
200 basic block because the program counter will always be at the same
201 location after the COND_EXEC instruction, regardless of whether the
202 condition is true or not.
204 Basic blocks need not start with a label nor end with a jump insn.
205 For example, a previous basic block may just "conditionally fall"
206 into the succeeding basic block, and the last basic block need not
207 end with a jump insn. Block 0 is a descendant of the entry block.
209 A basic block beginning with two labels cannot have notes between
212 Data for jump tables are stored in jump_insns that occur in no
213 basic block even though these insns can follow or precede insns in
216 /* Basic block information indexed by block number. */
217 struct basic_block_def GTY((chain_next ("%h.next_bb"), chain_prev ("%h.prev_bb")))
219 /* The first and last insns of the block. */
223 /* Pointers to the first and last trees of the block. */
226 /* The edges into and out of the block. */
230 /* The registers that are live on entry to this block. */
231 bitmap GTY ((skip (""))) global_live_at_start;
233 /* The registers that are live on exit from this block. */
234 bitmap GTY ((skip (""))) global_live_at_end;
236 /* Auxiliary info specific to a pass. */
237 PTR GTY ((skip (""))) aux;
239 /* Innermost loop containing the block. */
240 struct loop * GTY ((skip (""))) loop_father;
242 /* The dominance and postdominance information node. */
243 struct et_node * GTY ((skip (""))) dom[2];
245 /* Previous and next blocks in the chain. */
246 struct basic_block_def *prev_bb;
247 struct basic_block_def *next_bb;
249 /* The data used by basic block copying and reordering functions. */
250 struct reorder_block_def * rbi;
252 /* Chain of PHI nodes for this block. */
255 /* A list of predictions. */
256 struct edge_prediction *predictions;
258 /* Expected number of executions: calculated in profile.c. */
261 /* The index of this block. */
264 /* The loop depth of this block. */
267 /* Expected frequency. Normalized to be in range 0 to BB_FREQ_MAX. */
270 /* Various flags. See BB_* below. */
273 /* Which section block belongs in, when partitioning basic blocks. */
277 typedef struct basic_block_def *basic_block;
279 /* Structure to hold information about the blocks during reordering and
280 copying. Needs to be put on a diet. */
282 struct reorder_block_def GTY(())
289 /* These pointers may be unreliable as the first is only used for
290 debugging (and should probably be removed, and the second is only
291 used by copying. The basic blocks pointed to may be removed and
292 that leaves these pointers pointing to garbage. */
293 basic_block GTY ((skip (""))) original;
294 basic_block GTY ((skip (""))) copy;
299 /* This field is used by the bb-reorder and tracer passes. */
303 typedef struct reorder_block_def *reorder_block_def;
305 #define BB_FREQ_MAX 10000
307 /* Masks for basic_block.flags.
309 BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout
310 the compilation, so they are never cleared.
312 All other flags may be cleared by clear_bb_flags(). It is generally
313 a bad idea to rely on any flags being up-to-date. */
318 /* Set if insns in BB have are modified. Used for updating liveness info. */
321 /* Only set on blocks that have just been created by create_bb. */
324 /* Set by find_unreachable_blocks. Do not rely on this being set in any
328 /* Set for blocks in an irreducible loop by loop analysis. */
329 BB_IRREDUCIBLE_LOOP = 8,
331 /* Set on blocks that may actually not be single-entry single-exit block. */
334 /* Set on basic blocks that the scheduler should not touch. This is used
335 by SMS to prevent other schedulers from messing with the loop schedule. */
336 BB_DISABLE_SCHEDULE = 32,
338 /* Set on blocks that should be put in a hot section. */
339 BB_HOT_PARTITION = 64,
341 /* Set on blocks that should be put in a cold section. */
342 BB_COLD_PARTITION = 128
345 /* Dummy flag for convenience in the hot/cold partitioning code. */
346 #define BB_UNPARTITIONED 0
348 /* Partitions, to be used when partitioning hot and cold basic blocks into
349 separate sections. */
350 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
351 #define BB_SET_PARTITION(bb, part) do { \
352 basic_block bb_ = (bb); \
353 bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION)) \
357 #define BB_COPY_PARTITION(dstbb, srcbb) \
358 BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
360 /* A structure to group all the per-function control flow graph data.
361 The x_* prefixing is necessary because otherwise references to the
362 fields of this struct are interpreted as the defines for backward
363 source compatibility following the definition of this struct. */
364 struct control_flow_graph GTY(())
366 /* Block pointers for the exit and entry of a function.
367 These are always the head and tail of the basic block list. */
368 basic_block x_entry_block_ptr;
369 basic_block x_exit_block_ptr;
371 /* Index by basic block number, get basic block struct info. */
372 varray_type x_basic_block_info;
374 /* Number of basic blocks in this flow graph. */
375 int x_n_basic_blocks;
377 /* Number of edges in this flow graph. */
380 /* The first free basic block number. */
381 int x_last_basic_block;
383 /* Mapping of labels to their associated blocks. At present
384 only used for the tree CFG. */
385 varray_type x_label_to_block_map;
387 enum profile_status {
394 /* Defines for accessing the fields of the CFG structure for function FN. */
395 #define ENTRY_BLOCK_PTR_FOR_FUNCTION(FN) ((FN)->cfg->x_entry_block_ptr)
396 #define EXIT_BLOCK_PTR_FOR_FUNCTION(FN) ((FN)->cfg->x_exit_block_ptr)
397 #define basic_block_info_for_function(FN) ((FN)->cfg->x_basic_block_info)
398 #define n_basic_blocks_for_function(FN) ((FN)->cfg->x_n_basic_blocks)
399 #define n_edges_for_function(FN) ((FN)->cfg->x_n_edges)
400 #define last_basic_block_for_function(FN) ((FN)->cfg->x_last_basic_block)
401 #define label_to_block_map_for_function(FN) ((FN)->cfg->x_label_to_block_map)
403 #define BASIC_BLOCK_FOR_FUNCTION(FN,N) \
404 (VARRAY_BB (basic_block_info_for_function(FN), (N)))
406 /* Defines for textual backward source compatibility. */
407 #define ENTRY_BLOCK_PTR (cfun->cfg->x_entry_block_ptr)
408 #define EXIT_BLOCK_PTR (cfun->cfg->x_exit_block_ptr)
409 #define basic_block_info (cfun->cfg->x_basic_block_info)
410 #define n_basic_blocks (cfun->cfg->x_n_basic_blocks)
411 #define n_edges (cfun->cfg->x_n_edges)
412 #define last_basic_block (cfun->cfg->x_last_basic_block)
413 #define label_to_block_map (cfun->cfg->x_label_to_block_map)
414 #define profile_status (cfun->cfg->x_profile_status)
416 #define BASIC_BLOCK(N) (VARRAY_BB (basic_block_info, (N)))
418 /* TRUE if we should re-run loop discovery after threading jumps, FALSE
420 extern bool rediscover_loops_after_threading;
422 /* For iterating over basic blocks. */
423 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
424 for (BB = FROM; BB != TO; BB = BB->DIR)
426 #define FOR_EACH_BB_FN(BB, FN) \
427 FOR_BB_BETWEEN (BB, (FN)->cfg->x_entry_block_ptr->next_bb, (FN)->cfg->x_exit_block_ptr, next_bb)
429 #define FOR_EACH_BB(BB) FOR_EACH_BB_FN (BB, cfun)
431 #define FOR_EACH_BB_REVERSE_FN(BB, FN) \
432 FOR_BB_BETWEEN (BB, (FN)->cfg->x_exit_block_ptr->prev_bb, (FN)->cfg->x_entry_block_ptr, prev_bb)
434 #define FOR_EACH_BB_REVERSE(BB) FOR_EACH_BB_REVERSE_FN(BB, cfun)
436 /* For iterating over insns in basic block. */
437 #define FOR_BB_INSNS(BB, INSN) \
438 for ((INSN) = BB_HEAD (BB); \
439 (INSN) != NEXT_INSN (BB_END (BB)); \
440 (INSN) = NEXT_INSN (INSN))
442 #define FOR_BB_INSNS_REVERSE(BB, INSN) \
443 for ((INSN) = BB_END (BB); \
444 (INSN) != PREV_INSN (BB_HEAD (BB)); \
445 (INSN) = PREV_INSN (INSN))
447 /* Cycles through _all_ basic blocks, even the fake ones (entry and
450 #define FOR_ALL_BB(BB) \
451 for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
453 #define FOR_ALL_BB_FN(BB, FN) \
454 for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb)
456 /* Special labels found during CFG build. */
458 extern GTY(()) rtx label_value_list;
460 extern bitmap_obstack reg_obstack;
462 /* Indexed by n, gives number of basic block that (REG n) is used in.
463 If the value is REG_BLOCK_GLOBAL (-2),
464 it means (REG n) is used in more than one basic block.
465 REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
466 This information remains valid for the rest of the compilation
467 of the current function; it is used to control register allocation. */
469 #define REG_BLOCK_UNKNOWN -1
470 #define REG_BLOCK_GLOBAL -2
472 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
474 /* Stuff for recording basic block info. */
476 #define BB_HEAD(B) (B)->head_
477 #define BB_END(B) (B)->end_
479 /* Special block numbers [markers] for entry and exit. */
480 #define ENTRY_BLOCK (-1)
481 #define EXIT_BLOCK (-2)
483 /* Special block number not valid for any block. */
484 #define INVALID_BLOCK (-3)
486 #define BLOCK_NUM(INSN) (BLOCK_FOR_INSN (INSN)->index + 0)
487 #define set_block_for_insn(INSN, BB) (BLOCK_FOR_INSN (INSN) = BB)
489 extern void compute_bb_for_insn (void);
490 extern void free_bb_for_insn (void);
491 extern void update_bb_for_insn (basic_block);
493 extern void free_basic_block_vars (void);
495 extern void insert_insn_on_edge (rtx, edge);
496 bool safe_insert_insn_on_edge (rtx, edge);
498 extern void commit_edge_insertions (void);
499 extern void commit_edge_insertions_watch_calls (void);
501 extern void remove_fake_edges (void);
502 extern void remove_fake_exit_edges (void);
503 extern void add_noreturn_fake_exit_edges (void);
504 extern void connect_infinite_loops_to_exit (void);
505 extern edge unchecked_make_edge (basic_block, basic_block, int);
506 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
507 extern edge make_edge (basic_block, basic_block, int);
508 extern edge make_single_succ_edge (basic_block, basic_block, int);
509 extern void remove_edge (edge);
510 extern void redirect_edge_succ (edge, basic_block);
511 extern edge redirect_edge_succ_nodup (edge, basic_block);
512 extern void redirect_edge_pred (edge, basic_block);
513 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
514 extern void clear_bb_flags (void);
515 extern void flow_reverse_top_sort_order_compute (int *);
516 extern int flow_depth_first_order_compute (int *, int *);
517 extern int dfs_enumerate_from (basic_block, int,
518 bool (*)(basic_block, void *),
519 basic_block *, int, void *);
520 extern void compute_dominance_frontiers (bitmap *);
521 extern void dump_edge_info (FILE *, edge, int);
522 extern void brief_dump_cfg (FILE *);
523 extern void clear_edges (void);
524 extern rtx first_insn_after_basic_block_note (basic_block);
525 extern void scale_bbs_frequencies_int (basic_block *, int, int, int);
526 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
529 /* Structure to group all of the information to process IF-THEN and
530 IF-THEN-ELSE blocks for the conditional execution support. This
531 needs to be in a public file in case the IFCVT macros call
532 functions passing the ce_if_block data structure. */
534 typedef struct ce_if_block
536 basic_block test_bb; /* First test block. */
537 basic_block then_bb; /* THEN block. */
538 basic_block else_bb; /* ELSE block or NULL. */
539 basic_block join_bb; /* Join THEN/ELSE blocks. */
540 basic_block last_test_bb; /* Last bb to hold && or || tests. */
541 int num_multiple_test_blocks; /* # of && and || basic blocks. */
542 int num_and_and_blocks; /* # of && blocks. */
543 int num_or_or_blocks; /* # of || blocks. */
544 int num_multiple_test_insns; /* # of insns in && and || blocks. */
545 int and_and_p; /* Complex test is &&. */
546 int num_then_insns; /* # of insns in THEN block. */
547 int num_else_insns; /* # of insns in ELSE block. */
548 int pass; /* Pass number. */
550 #ifdef IFCVT_EXTRA_FIELDS
551 IFCVT_EXTRA_FIELDS /* Any machine dependent fields. */
556 /* This structure maintains an edge list vector. */
564 /* The base value for branch probability notes and edge probabilities. */
565 #define REG_BR_PROB_BASE 10000
567 /* This is the value which indicates no edge is present. */
568 #define EDGE_INDEX_NO_EDGE -1
570 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
571 if there is no edge between the 2 basic blocks. */
572 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
574 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
575 block which is either the pred or succ end of the indexed edge. */
576 #define INDEX_EDGE_PRED_BB(el, index) ((el)->index_to_edge[(index)]->src)
577 #define INDEX_EDGE_SUCC_BB(el, index) ((el)->index_to_edge[(index)]->dest)
579 /* INDEX_EDGE returns a pointer to the edge. */
580 #define INDEX_EDGE(el, index) ((el)->index_to_edge[(index)])
582 /* Number of edges in the compressed edge list. */
583 #define NUM_EDGES(el) ((el)->num_edges)
585 /* BB is assumed to contain conditional jump. Return the fallthru edge. */
586 #define FALLTHRU_EDGE(bb) (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
587 ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
589 /* BB is assumed to contain conditional jump. Return the branch edge. */
590 #define BRANCH_EDGE(bb) (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
591 ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
593 /* Return expected execution frequency of the edge E. */
594 #define EDGE_FREQUENCY(e) (((e)->src->frequency \
596 + REG_BR_PROB_BASE / 2) \
599 /* Return nonzero if edge is critical. */
600 #define EDGE_CRITICAL_P(e) (EDGE_COUNT ((e)->src->succs) >= 2 \
601 && EDGE_COUNT ((e)->dest->preds) >= 2)
603 #define EDGE_COUNT(ev) VEC_length (edge, (ev))
604 #define EDGE_I(ev,i) VEC_index (edge, (ev), (i))
605 #define EDGE_PRED(bb,i) VEC_index (edge, (bb)->preds, (i))
606 #define EDGE_SUCC(bb,i) VEC_index (edge, (bb)->succs, (i))
608 /* Returns true if BB has precisely one successor. */
611 single_succ_p (basic_block bb)
613 return EDGE_COUNT (bb->succs) == 1;
616 /* Returns true if BB has precisely one predecessor. */
619 single_pred_p (basic_block bb)
621 return EDGE_COUNT (bb->preds) == 1;
624 /* Returns the single successor edge of basic block BB. Aborts if
625 BB does not have exactly one successor. */
628 single_succ_edge (basic_block bb)
630 gcc_assert (single_succ_p (bb));
631 return EDGE_SUCC (bb, 0);
634 /* Returns the single predecessor edge of basic block BB. Aborts
635 if BB does not have exactly one predecessor. */
638 single_pred_edge (basic_block bb)
640 gcc_assert (single_pred_p (bb));
641 return EDGE_PRED (bb, 0);
644 /* Returns the single successor block of basic block BB. Aborts
645 if BB does not have exactly one successor. */
647 static inline basic_block
648 single_succ (basic_block bb)
650 return single_succ_edge (bb)->dest;
653 /* Returns the single predecessor block of basic block BB. Aborts
654 if BB does not have exactly one predecessor.*/
656 static inline basic_block
657 single_pred (basic_block bb)
659 return single_pred_edge (bb)->src;
662 /* Iterator object for edges. */
666 VEC(edge,gc) **container;
669 static inline VEC(edge,gc) *
670 ei_container (edge_iterator i)
672 gcc_assert (i.container);
676 #define ei_start(iter) ei_start_1 (&(iter))
677 #define ei_last(iter) ei_last_1 (&(iter))
679 /* Return an iterator pointing to the start of an edge vector. */
680 static inline edge_iterator
681 ei_start_1 (VEC(edge,gc) **ev)
691 /* Return an iterator pointing to the last element of an edge
693 static inline edge_iterator
694 ei_last_1 (VEC(edge,gc) **ev)
698 i.index = EDGE_COUNT (*ev) - 1;
704 /* Is the iterator `i' at the end of the sequence? */
706 ei_end_p (edge_iterator i)
708 return (i.index == EDGE_COUNT (ei_container (i)));
711 /* Is the iterator `i' at one position before the end of the
714 ei_one_before_end_p (edge_iterator i)
716 return (i.index + 1 == EDGE_COUNT (ei_container (i)));
719 /* Advance the iterator to the next element. */
721 ei_next (edge_iterator *i)
723 gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
727 /* Move the iterator to the previous element. */
729 ei_prev (edge_iterator *i)
731 gcc_assert (i->index > 0);
735 /* Return the edge pointed to by the iterator `i'. */
737 ei_edge (edge_iterator i)
739 return EDGE_I (ei_container (i), i.index);
742 /* Return an edge pointed to by the iterator. Do it safely so that
743 NULL is returned when the iterator is pointing at the end of the
746 ei_safe_edge (edge_iterator i)
748 return !ei_end_p (i) ? ei_edge (i) : NULL;
751 /* Return 1 if we should continue to iterate. Return 0 otherwise.
752 *Edge P is set to the next edge if we are to continue to iterate
753 and NULL otherwise. */
756 ei_cond (edge_iterator ei, edge *p)
770 /* This macro serves as a convenient way to iterate each edge in a
771 vector of predecessor or successor edges. It must not be used when
772 an element might be removed during the traversal, otherwise
773 elements will be missed. Instead, use a for-loop like that shown
774 in the following pseudo-code:
776 FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
785 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC) \
786 for ((ITER) = ei_start ((EDGE_VEC)); \
787 ei_cond ((ITER), &(EDGE)); \
790 struct edge_list * create_edge_list (void);
791 void free_edge_list (struct edge_list *);
792 void print_edge_list (FILE *, struct edge_list *);
793 void verify_edge_list (FILE *, struct edge_list *);
794 int find_edge_index (struct edge_list *, basic_block, basic_block);
795 edge find_edge (basic_block, basic_block);
798 enum update_life_extent
800 UPDATE_LIFE_LOCAL = 0,
801 UPDATE_LIFE_GLOBAL = 1,
802 UPDATE_LIFE_GLOBAL_RM_NOTES = 2
805 /* Flags for life_analysis and update_life_info. */
807 #define PROP_DEATH_NOTES 1 /* Create DEAD and UNUSED notes. */
808 #define PROP_LOG_LINKS 2 /* Create LOG_LINKS. */
809 #define PROP_REG_INFO 4 /* Update regs_ever_live et al. */
810 #define PROP_KILL_DEAD_CODE 8 /* Remove dead code. */
811 #define PROP_SCAN_DEAD_CODE 16 /* Scan for dead code. */
812 #define PROP_ALLOW_CFG_CHANGES 32 /* Allow the CFG to be changed
813 by dead code removal. */
814 #define PROP_AUTOINC 64 /* Create autoinc mem references. */
815 #define PROP_SCAN_DEAD_STORES 128 /* Scan for dead code. */
816 #define PROP_ASM_SCAN 256 /* Internal flag used within flow.c
817 to flag analysis of asms. */
818 #define PROP_DEAD_INSN 1024 /* Internal flag used within flow.c
819 to flag analysis of dead insn. */
820 #define PROP_FINAL (PROP_DEATH_NOTES | PROP_LOG_LINKS \
821 | PROP_REG_INFO | PROP_KILL_DEAD_CODE \
822 | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
823 | PROP_ALLOW_CFG_CHANGES \
824 | PROP_SCAN_DEAD_STORES)
825 #define PROP_POSTRELOAD (PROP_DEATH_NOTES \
826 | PROP_KILL_DEAD_CODE \
827 | PROP_SCAN_DEAD_CODE \
828 | PROP_SCAN_DEAD_STORES)
830 #define CLEANUP_EXPENSIVE 1 /* Do relatively expensive optimizations
831 except for edge forwarding */
832 #define CLEANUP_CROSSJUMP 2 /* Do crossjumping. */
833 #define CLEANUP_POST_REGSTACK 4 /* We run after reg-stack and need
834 to care REG_DEAD notes. */
835 #define CLEANUP_PRE_LOOP 8 /* Take care to preserve syntactic loop
837 #define CLEANUP_UPDATE_LIFE 16 /* Keep life information up to date. */
838 #define CLEANUP_THREADING 32 /* Do jump threading. */
839 #define CLEANUP_NO_INSN_DEL 64 /* Do not try to delete trivially dead
841 #define CLEANUP_CFGLAYOUT 128 /* Do cleanup in cfglayout mode. */
842 #define CLEANUP_LOG_LINKS 256 /* Update log links. */
844 extern void life_analysis (FILE *, int);
845 extern int update_life_info (sbitmap, enum update_life_extent, int);
846 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
847 extern int count_or_remove_death_notes (sbitmap, int);
848 extern int propagate_block (basic_block, regset, regset, regset, int);
850 struct propagate_block_info;
851 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
852 extern struct propagate_block_info *init_propagate_block_info
853 (basic_block, regset, regset, regset, int);
854 extern void free_propagate_block_info (struct propagate_block_info *);
857 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
858 sbitmap *, sbitmap *, sbitmap **,
860 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
861 sbitmap *, sbitmap *,
862 sbitmap *, sbitmap **,
864 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
865 extern int optimize_mode_switching (FILE *);
868 extern void estimate_probability (struct loops *);
869 extern void expected_value_to_br_prob (void);
870 extern bool maybe_hot_bb_p (basic_block);
871 extern bool probably_cold_bb_p (basic_block);
872 extern bool probably_never_executed_bb_p (basic_block);
873 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
874 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
875 extern void tree_predict_edge (edge, enum br_predictor, int);
876 extern void rtl_predict_edge (edge, enum br_predictor, int);
877 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
878 extern void guess_outgoing_edge_probabilities (basic_block);
881 extern void init_flow (void);
882 extern void debug_bb (basic_block);
883 extern basic_block debug_bb_n (int);
884 extern void dump_regset (regset, FILE *);
885 extern void debug_regset (regset);
886 extern void allocate_reg_life_data (void);
887 extern void expunge_block (basic_block);
888 extern void link_block (basic_block, basic_block);
889 extern void unlink_block (basic_block);
890 extern void compact_blocks (void);
891 extern basic_block alloc_block (void);
892 extern void find_unreachable_blocks (void);
893 extern int delete_noop_moves (void);
894 extern basic_block force_nonfallthru (edge);
895 extern rtx block_label (basic_block);
896 extern bool forwarder_block_p (basic_block);
897 extern bool purge_all_dead_edges (void);
898 extern bool purge_dead_edges (basic_block);
899 extern void find_many_sub_basic_blocks (sbitmap);
900 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx);
901 extern bool can_fallthru (basic_block, basic_block);
902 extern bool could_fall_through (basic_block, basic_block);
903 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
904 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
905 extern void alloc_aux_for_block (basic_block, int);
906 extern void alloc_aux_for_blocks (int);
907 extern void clear_aux_for_blocks (void);
908 extern void free_aux_for_blocks (void);
909 extern void alloc_aux_for_edge (edge, int);
910 extern void alloc_aux_for_edges (int);
911 extern void clear_aux_for_edges (void);
912 extern void free_aux_for_edges (void);
913 extern void find_basic_blocks (rtx);
914 extern bool cleanup_cfg (int);
915 extern bool delete_unreachable_blocks (void);
916 extern bool merge_seq_blocks (void);
918 typedef struct conflict_graph_def *conflict_graph;
920 /* Callback function when enumerating conflicts. The arguments are
921 the smaller and larger regno in the conflict. Returns zero if
922 enumeration is to continue, nonzero to halt enumeration. */
923 typedef int (*conflict_graph_enum_fn) (int, int, void *);
926 /* Prototypes of operations on conflict graphs. */
928 extern conflict_graph conflict_graph_new
930 extern void conflict_graph_delete (conflict_graph);
931 extern int conflict_graph_add (conflict_graph, int, int);
932 extern int conflict_graph_conflict_p (conflict_graph, int, int);
933 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
935 extern void conflict_graph_merge_regs (conflict_graph, int, int);
936 extern void conflict_graph_print (conflict_graph, FILE*);
937 extern bool mark_dfs_back_edges (void);
938 extern void set_edge_can_fallthru_flag (void);
939 extern void update_br_prob_note (basic_block);
940 extern void fixup_abnormal_edges (void);
941 extern bool inside_basic_block_p (rtx);
942 extern bool control_flow_insn_p (rtx);
944 /* In bb-reorder.c */
945 extern void reorder_basic_blocks (unsigned int);
946 extern void duplicate_computed_gotos (void);
947 extern void partition_hot_cold_basic_blocks (void);
950 extern void initialize_bb_rbi (basic_block bb);
962 DOM_NONE, /* Not computed at all. */
963 DOM_NO_FAST_QUERY, /* The data is OK, but the fast query data are not usable. */
964 DOM_OK /* Everything is ok. */
967 extern enum dom_state dom_computed[2];
969 extern bool dom_info_available_p (enum cdi_direction);
970 extern void calculate_dominance_info (enum cdi_direction);
971 extern void free_dominance_info (enum cdi_direction);
972 extern basic_block nearest_common_dominator (enum cdi_direction,
973 basic_block, basic_block);
974 extern basic_block nearest_common_dominator_for_set (enum cdi_direction,
976 extern void set_immediate_dominator (enum cdi_direction, basic_block,
978 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
979 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
980 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
981 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
982 unsigned, basic_block *);
983 extern void add_to_dominance_info (enum cdi_direction, basic_block);
984 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
985 basic_block recount_dominator (enum cdi_direction, basic_block);
986 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
988 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
989 extern void verify_dominators (enum cdi_direction);
990 extern basic_block first_dom_son (enum cdi_direction, basic_block);
991 extern basic_block next_dom_son (enum cdi_direction, basic_block);
992 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
993 extern void break_superblocks (void);
994 extern void check_bb_profile (basic_block, FILE *);
995 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
997 #include "cfghooks.h"
999 #endif /* GCC_BASIC_BLOCK_H */