basic-block.h revision 117395
1/* Define control and data flow tables, and regsets.
2   Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003
3   Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING.  If not, write to the Free
19Software Foundation, 59 Temple Place - Suite 330, Boston, MA
2002111-1307, USA.  */
21
22#ifndef GCC_BASIC_BLOCK_H
23#define GCC_BASIC_BLOCK_H
24
25#include "bitmap.h"
26#include "sbitmap.h"
27#include "varray.h"
28#include "partition.h"
29#include "hard-reg-set.h"
30
31/* Head of register set linked list.  */
32typedef bitmap_head regset_head;
33/* A pointer to a regset_head.  */
34typedef bitmap regset;
35
36/* Initialize a new regset.  */
37#define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, 1)
38
39/* Clear a register set by freeing up the linked list.  */
40#define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
41
42/* Copy a register set to another register set.  */
43#define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
44
45/* Compare two register sets.  */
46#define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
47
48/* `and' a register set with a second register set.  */
49#define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
50
51/* `and' the complement of a register set with a register set.  */
52#define AND_COMPL_REG_SET(TO, FROM) \
53  bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
54
55/* Inclusive or a register set with a second register set.  */
56#define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
57
58/* Exclusive or a register set with a second register set.  */
59#define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
60
61/* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
62#define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
63  bitmap_ior_and_compl (TO, FROM1, FROM2)
64
65/* Clear a single register in a register set.  */
66#define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
67
68/* Set a single register in a register set.  */
69#define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
70
71/* Return true if a register is set in a register set.  */
72#define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
73
74/* Copy the hard registers in a register set to the hard register set.  */
75extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
76#define REG_SET_TO_HARD_REG_SET(TO, FROM)				\
77do {									\
78  CLEAR_HARD_REG_SET (TO);						\
79  reg_set_to_hard_reg_set (&TO, FROM);					\
80} while (0)
81
82/* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
83   register number and executing CODE for all registers that are set.  */
84#define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)		\
85  EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
86
87/* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
88   REGNUM to the register number and executing CODE for all registers that are
89   set in the first regset and not set in the second.  */
90#define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
91  EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
92
93/* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
94   REGNUM to the register number and executing CODE for all registers that are
95   set in both regsets.  */
96#define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
97  EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
98
99/* Allocate a register set with oballoc.  */
100#define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
101
102/* Initialize a register set.  Returns the new register set.  */
103#define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD, 1)
104
105/* Do any cleanup needed on a regset when it is no longer used.  */
106#define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
107
108/* Do any one-time initializations needed for regsets.  */
109#define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
110
111/* Grow any tables needed when the number of registers is calculated
112   or extended.  For the linked list allocation, nothing needs to
113   be done, other than zero the statistics on the first allocation.  */
114#define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
115
116/* Type we use to hold basic block counters.  Should be at least 64bit.  */
117typedef HOST_WIDEST_INT gcov_type;
118
119/* Control flow edge information.  */
120typedef struct edge_def {
121  /* Links through the predecessor and successor lists.  */
122  struct edge_def *pred_next, *succ_next;
123
124  /* The two blocks at the ends of the edge.  */
125  struct basic_block_def *src, *dest;
126
127  /* Instructions queued on the edge.  */
128  rtx insns;
129
130  /* Auxiliary info specific to a pass.  */
131  void *aux;
132
133  int flags;			/* see EDGE_* below  */
134  int probability;		/* biased by REG_BR_PROB_BASE */
135  gcov_type count;		/* Expected number of executions calculated
136				   in profile.c  */
137} *edge;
138
139#define EDGE_FALLTHRU		1	/* 'Straight line' flow */
140#define EDGE_ABNORMAL		2	/* Strange flow, like computed
141					   label, or eh */
142#define EDGE_ABNORMAL_CALL	4	/* Call with abnormal exit
143					   like an exception, or sibcall */
144#define EDGE_EH			8	/* Exception throw */
145#define EDGE_FAKE		16	/* Not a real edge (profile.c) */
146#define EDGE_DFS_BACK		32	/* A backwards edge */
147#define EDGE_CAN_FALLTHRU	64	/* Candidate for straight line
148					   flow.  */
149
150#define EDGE_COMPLEX	(EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
151
152
153/* A basic block is a sequence of instructions with only entry and
154   only one exit.  If any one of the instructions are executed, they
155   will all be executed, and in sequence from first to last.
156
157   There may be COND_EXEC instructions in the basic block.  The
158   COND_EXEC *instructions* will be executed -- but if the condition
159   is false the conditionally executed *expressions* will of course
160   not be executed.  We don't consider the conditionally executed
161   expression (which might have side-effects) to be in a separate
162   basic block because the program counter will always be at the same
163   location after the COND_EXEC instruction, regardless of whether the
164   condition is true or not.
165
166   Basic blocks need not start with a label nor end with a jump insn.
167   For example, a previous basic block may just "conditionally fall"
168   into the succeeding basic block, and the last basic block need not
169   end with a jump insn.  Block 0 is a descendant of the entry block.
170
171   A basic block beginning with two labels cannot have notes between
172   the labels.
173
174   Data for jump tables are stored in jump_insns that occur in no
175   basic block even though these insns can follow or precede insns in
176   basic blocks.  */
177
178/* Basic block information indexed by block number.  */
179typedef struct basic_block_def {
180  /* The first and last insns of the block.  */
181  rtx head, end;
182
183  /* The first and last trees of the block.  */
184  tree head_tree;
185  tree end_tree;
186
187  /* The edges into and out of the block.  */
188  edge pred, succ;
189
190  /* Liveness info.  */
191
192  /* The registers that are modified within this in block.  */
193  regset local_set;
194  /* The registers that are conditionally modified within this block.
195     In other words, registers that are set only as part of a
196     COND_EXEC.  */
197  regset cond_local_set;
198  /* The registers that are live on entry to this block.
199
200     Note that in SSA form, global_live_at_start does not reflect the
201     use of regs in phi functions, since the liveness of these regs
202     may depend on which edge was taken into the block.  */
203  regset global_live_at_start;
204  /* The registers that are live on exit from this block.  */
205  regset global_live_at_end;
206
207  /* Auxiliary info specific to a pass.  */
208  void *aux;
209
210  /* The index of this block.  */
211  int index;
212
213  /* Previous and next blocks in the chain.  */
214  struct basic_block_def *prev_bb, *next_bb;
215
216  /* The loop depth of this block.  */
217  int loop_depth;
218
219  /* Outermost loop containing the block.  */
220  struct loop *loop_father;
221
222  /* Expected number of executions: calculated in profile.c.  */
223  gcov_type count;
224
225  /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
226  int frequency;
227
228  /* Various flags.  See BB_* below.  */
229  int flags;
230} *basic_block;
231
232#define BB_FREQ_MAX 10000
233
234/* Masks for basic_block.flags.  */
235#define BB_DIRTY		1
236#define BB_NEW			2
237#define BB_REACHABLE		4
238#define BB_VISITED		8
239
240/* Number of basic blocks in the current function.  */
241
242extern int n_basic_blocks;
243
244/* First free basic block number.  */
245
246extern int last_basic_block;
247
248/* Number of edges in the current function.  */
249
250extern int n_edges;
251
252/* Index by basic block number, get basic block struct info.  */
253
254extern varray_type basic_block_info;
255
256#define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
257
258/* For iterating over basic blocks.  */
259#define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
260  for (BB = FROM; BB != TO; BB = BB->DIR)
261
262#define FOR_EACH_BB(BB) \
263  FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
264
265#define FOR_EACH_BB_REVERSE(BB) \
266  FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)
267
268/* Cycles through _all_ basic blocks, even the fake ones (entry and
269   exit block).  */
270
271#define FOR_ALL_BB(BB) \
272  for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
273
274/* What registers are live at the setjmp call.  */
275
276extern regset regs_live_at_setjmp;
277
278/* Special labels found during CFG build.  */
279
280extern GTY(()) rtx label_value_list;
281extern GTY(()) rtx tail_recursion_label_list;
282
283extern struct obstack flow_obstack;
284
285/* Indexed by n, gives number of basic block that  (REG n) is used in.
286   If the value is REG_BLOCK_GLOBAL (-2),
287   it means (REG n) is used in more than one basic block.
288   REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
289   This information remains valid for the rest of the compilation
290   of the current function; it is used to control register allocation.  */
291
292#define REG_BLOCK_UNKNOWN -1
293#define REG_BLOCK_GLOBAL -2
294
295#define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
296
297/* Stuff for recording basic block info.  */
298
299#define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
300#define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
301
302#define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
303#define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
304
305/* Special block numbers [markers] for entry and exit.  */
306#define ENTRY_BLOCK (-1)
307#define EXIT_BLOCK (-2)
308
309/* Special block number not valid for any block.  */
310#define INVALID_BLOCK (-3)
311
312/* Similarly, block pointers for the edge list.  */
313extern struct basic_block_def entry_exit_blocks[2];
314#define ENTRY_BLOCK_PTR	(&entry_exit_blocks[0])
315#define EXIT_BLOCK_PTR	(&entry_exit_blocks[1])
316
317#define BLOCK_NUM(INSN)	      (BLOCK_FOR_INSN (INSN)->index + 0)
318#define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
319
320extern void compute_bb_for_insn		PARAMS ((void));
321extern void free_bb_for_insn		PARAMS ((void));
322extern void update_bb_for_insn		PARAMS ((basic_block));
323
324extern void free_basic_block_vars	PARAMS ((int));
325
326extern edge split_block			PARAMS ((basic_block, rtx));
327extern basic_block split_edge		PARAMS ((edge));
328extern void insert_insn_on_edge		PARAMS ((rtx, edge));
329
330extern void commit_edge_insertions	PARAMS ((void));
331extern void commit_edge_insertions_watch_calls	PARAMS ((void));
332
333extern void remove_fake_edges		PARAMS ((void));
334extern void add_noreturn_fake_exit_edges	PARAMS ((void));
335extern void connect_infinite_loops_to_exit	PARAMS ((void));
336extern int flow_call_edges_add		PARAMS ((sbitmap));
337extern edge cached_make_edge		PARAMS ((sbitmap *, basic_block,
338						 basic_block, int));
339extern edge unchecked_make_edge		PARAMS ((basic_block,
340						 basic_block, int));
341extern edge make_edge			PARAMS ((basic_block,
342						 basic_block, int));
343extern edge make_single_succ_edge	PARAMS ((basic_block,
344						 basic_block, int));
345extern void remove_edge			PARAMS ((edge));
346extern void redirect_edge_succ		PARAMS ((edge, basic_block));
347extern edge redirect_edge_succ_nodup	PARAMS ((edge, basic_block));
348extern void redirect_edge_pred		PARAMS ((edge, basic_block));
349extern basic_block create_basic_block_structure PARAMS ((rtx, rtx, rtx, basic_block));
350extern basic_block create_basic_block	PARAMS ((rtx, rtx, basic_block));
351extern int flow_delete_block		PARAMS ((basic_block));
352extern int flow_delete_block_noexpunge	PARAMS ((basic_block));
353extern void clear_bb_flags		PARAMS ((void));
354extern void merge_blocks_nomove		PARAMS ((basic_block, basic_block));
355extern void tidy_fallthru_edge		PARAMS ((edge, basic_block,
356						 basic_block));
357extern void tidy_fallthru_edges		PARAMS ((void));
358extern void flow_reverse_top_sort_order_compute	PARAMS ((int *));
359extern int flow_depth_first_order_compute	PARAMS ((int *, int *));
360extern void flow_preorder_transversal_compute	PARAMS ((int *));
361extern void dump_edge_info		PARAMS ((FILE *, edge, int));
362extern void clear_edges			PARAMS ((void));
363extern void mark_critical_edges		PARAMS ((void));
364extern rtx first_insn_after_basic_block_note	PARAMS ((basic_block));
365
366/* Dominator information for basic blocks.  */
367
368typedef struct dominance_info *dominance_info;
369
370/* Structure to hold information for each natural loop.  */
371struct loop
372{
373  /* Index into loops array.  */
374  int num;
375
376  /* Basic block of loop header.  */
377  basic_block header;
378
379  /* Basic block of loop latch.  */
380  basic_block latch;
381
382  /* Basic block of loop pre-header or NULL if it does not exist.  */
383  basic_block pre_header;
384
385  /* Array of edges along the pre-header extended basic block trace.
386     The source of the first edge is the root node of pre-header
387     extended basic block, if it exists.  */
388  edge *pre_header_edges;
389
390  /* Number of edges along the pre_header extended basic block trace.  */
391  int num_pre_header_edges;
392
393  /* The first block in the loop.  This is not necessarily the same as
394     the loop header.  */
395  basic_block first;
396
397  /* The last block in the loop.  This is not necessarily the same as
398     the loop latch.  */
399  basic_block last;
400
401  /* Bitmap of blocks contained within the loop.  */
402  sbitmap nodes;
403
404  /* Number of blocks contained within the loop.  */
405  int num_nodes;
406
407  /* Array of edges that enter the loop.  */
408  edge *entry_edges;
409
410  /* Number of edges that enter the loop.  */
411  int num_entries;
412
413  /* Array of edges that exit the loop.  */
414  edge *exit_edges;
415
416  /* Number of edges that exit the loop.  */
417  int num_exits;
418
419  /* Bitmap of blocks that dominate all exits of the loop.  */
420  sbitmap exits_doms;
421
422  /* The loop nesting depth.  */
423  int depth;
424
425  /* Superloops of the loop.  */
426  struct loop **pred;
427
428  /* The height of the loop (enclosed loop levels) within the loop
429     hierarchy tree.  */
430  int level;
431
432  /* The outer (parent) loop or NULL if outermost loop.  */
433  struct loop *outer;
434
435  /* The first inner (child) loop or NULL if innermost loop.  */
436  struct loop *inner;
437
438  /* Link to the next (sibling) loop.  */
439  struct loop *next;
440
441  /* Nonzero if the loop is invalid (e.g., contains setjmp.).  */
442  int invalid;
443
444  /* Auxiliary info specific to a pass.  */
445  void *aux;
446
447  /* The following are currently used by loop.c but they are likely to
448     disappear as loop.c is converted to use the CFG.  */
449
450  /* Nonzero if the loop has a NOTE_INSN_LOOP_VTOP.  */
451  rtx vtop;
452
453  /* Nonzero if the loop has a NOTE_INSN_LOOP_CONT.
454     A continue statement will generate a branch to NEXT_INSN (cont).  */
455  rtx cont;
456
457  /* The NOTE_INSN_LOOP_BEG.  */
458  rtx start;
459
460  /* The NOTE_INSN_LOOP_END.  */
461  rtx end;
462
463  /* For a rotated loop that is entered near the bottom,
464     this is the label at the top.  Otherwise it is zero.  */
465  rtx top;
466
467  /* Place in the loop where control enters.  */
468  rtx scan_start;
469
470  /* The position where to sink insns out of the loop.  */
471  rtx sink;
472
473  /* List of all LABEL_REFs which refer to code labels outside the
474     loop.  Used by routines that need to know all loop exits, such as
475     final_biv_value and final_giv_value.
476
477     This does not include loop exits due to return instructions.
478     This is because all bivs and givs are pseudos, and hence must be
479     dead after a return, so the presense of a return does not affect
480     any of the optimizations that use this info.  It is simpler to
481     just not include return instructions on this list.  */
482  rtx exit_labels;
483
484  /* The number of LABEL_REFs on exit_labels for this loop and all
485     loops nested inside it.  */
486  int exit_count;
487};
488
489
490/* Structure to hold CFG information about natural loops within a function.  */
491struct loops
492{
493  /* Number of natural loops in the function.  */
494  int num;
495
496  /* Maxium nested loop level in the function.  */
497  int levels;
498
499  /* Array of natural loop descriptors (scanning this array in reverse order
500     will find the inner loops before their enclosing outer loops).  */
501  struct loop *array;
502
503  /* The above array is unused in new loop infrastructure and is kept only for
504     purposes of the old loop optimizer.  Instead we store just pointers to
505     loops here.  */
506  struct loop **parray;
507
508  /* Pointer to root of loop heirachy tree.  */
509  struct loop *tree_root;
510
511  /* Information derived from the CFG.  */
512  struct cfg
513  {
514    /* The bitmap vector of dominators or NULL if not computed.  */
515    dominance_info dom;
516
517    /* The ordering of the basic blocks in a depth first search.  */
518    int *dfs_order;
519
520    /* The reverse completion ordering of the basic blocks found in a
521       depth first search.  */
522    int *rc_order;
523  } cfg;
524
525  /* Headers shared by multiple loops that should be merged.  */
526  sbitmap shared_headers;
527};
528
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.  */
533
534typedef struct ce_if_block
535{
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.  */
549
550#ifdef IFCVT_EXTRA_FIELDS
551  IFCVT_EXTRA_FIELDS			/* Any machine dependent fields.  */
552#endif
553
554} ce_if_block_t;
555
556extern int flow_loops_find PARAMS ((struct loops *, int flags));
557extern int flow_loops_update PARAMS ((struct loops *, int flags));
558extern void flow_loops_free PARAMS ((struct loops *));
559extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
560				     void (*)(const struct loop *,
561					      FILE *, int), int));
562extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
563				    void (*)(const struct loop *,
564					     FILE *, int), int));
565extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
566extern void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *));
567extern void flow_loop_tree_node_remove PARAMS ((struct loop *));
568
569/* This structure maintains an edge list vector.  */
570struct edge_list
571{
572  int num_blocks;
573  int num_edges;
574  edge *index_to_edge;
575};
576
577/* This is the value which indicates no edge is present.  */
578#define EDGE_INDEX_NO_EDGE	-1
579
580/* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
581   if there is no edge between the 2 basic blocks.  */
582#define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
583
584/* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
585   block which is either the pred or succ end of the indexed edge.  */
586#define INDEX_EDGE_PRED_BB(el, index)	((el)->index_to_edge[(index)]->src)
587#define INDEX_EDGE_SUCC_BB(el, index)	((el)->index_to_edge[(index)]->dest)
588
589/* INDEX_EDGE returns a pointer to the edge.  */
590#define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
591
592/* Number of edges in the compressed edge list.  */
593#define NUM_EDGES(el)			((el)->num_edges)
594
595/* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
596#define FALLTHRU_EDGE(bb)		((bb)->succ->flags & EDGE_FALLTHRU \
597					 ? (bb)->succ : (bb)->succ->succ_next)
598
599/* BB is assumed to contain conditional jump.  Return the branch edge.  */
600#define BRANCH_EDGE(bb)			((bb)->succ->flags & EDGE_FALLTHRU \
601					 ? (bb)->succ->succ_next : (bb)->succ)
602
603/* Return expected execution frequency of the edge E.  */
604#define EDGE_FREQUENCY(e)		(((e)->src->frequency \
605					  * (e)->probability \
606					  + REG_BR_PROB_BASE / 2) \
607					 / REG_BR_PROB_BASE)
608
609/* Return nonzero if edge is critical.  */
610#define EDGE_CRITICAL_P(e)		((e)->src->succ->succ_next \
611					 && (e)->dest->pred->pred_next)
612
613struct edge_list * create_edge_list	PARAMS ((void));
614void free_edge_list			PARAMS ((struct edge_list *));
615void print_edge_list			PARAMS ((FILE *, struct edge_list *));
616void verify_edge_list			PARAMS ((FILE *, struct edge_list *));
617int find_edge_index			PARAMS ((struct edge_list *,
618						 basic_block, basic_block));
619
620
621enum update_life_extent
622{
623  UPDATE_LIFE_LOCAL = 0,
624  UPDATE_LIFE_GLOBAL = 1,
625  UPDATE_LIFE_GLOBAL_RM_NOTES = 2
626};
627
628/* Flags for life_analysis and update_life_info.  */
629
630#define PROP_DEATH_NOTES	1	/* Create DEAD and UNUSED notes.  */
631#define PROP_LOG_LINKS		2	/* Create LOG_LINKS.  */
632#define PROP_REG_INFO		4	/* Update regs_ever_live et al.  */
633#define PROP_KILL_DEAD_CODE	8	/* Remove dead code.  */
634#define PROP_SCAN_DEAD_CODE	16	/* Scan for dead code.  */
635#define PROP_ALLOW_CFG_CHANGES	32	/* Allow the CFG to be changed
636					   by dead code removal.  */
637#define PROP_AUTOINC		64	/* Create autoinc mem references.  */
638#define PROP_EQUAL_NOTES	128	/* Take into account REG_EQUAL notes.  */
639#define PROP_SCAN_DEAD_STORES	256	/* Scan for dead code.  */
640#define PROP_FINAL		(PROP_DEATH_NOTES | PROP_LOG_LINKS  \
641				 | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
642				 | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
643				 | PROP_ALLOW_CFG_CHANGES \
644				 | PROP_SCAN_DEAD_STORES)
645
646#define CLEANUP_EXPENSIVE	1	/* Do relativly expensive optimizations
647					   except for edge forwarding */
648#define CLEANUP_CROSSJUMP	2	/* Do crossjumping.  */
649#define CLEANUP_POST_REGSTACK	4	/* We run after reg-stack and need
650					   to care REG_DEAD notes.  */
651#define CLEANUP_PRE_SIBCALL	8	/* Do not get confused by code hidden
652					   inside call_placeholders..  */
653#define CLEANUP_PRE_LOOP	16	/* Take care to preserve syntactic loop
654					   notes.  */
655#define CLEANUP_UPDATE_LIFE	32	/* Keep life information up to date.  */
656#define CLEANUP_THREADING	64	/* Do jump threading.  */
657#define CLEANUP_NO_INSN_DEL	128	/* Do not try to delete trivially dead
658					   insns.  */
659/* Flags for loop discovery.  */
660
661#define LOOP_TREE		1	/* Build loop hierarchy tree.  */
662#define LOOP_PRE_HEADER		2	/* Analyse loop pre-header.  */
663#define LOOP_ENTRY_EDGES	4	/* Find entry edges.  */
664#define LOOP_EXIT_EDGES		8	/* Find exit edges.  */
665#define LOOP_EDGES		(LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
666#define LOOP_ALL	       15	/* All of the above  */
667
668extern void life_analysis	PARAMS ((rtx, FILE *, int));
669extern int update_life_info	PARAMS ((sbitmap, enum update_life_extent,
670					 int));
671extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
672						      int));
673extern int count_or_remove_death_notes	PARAMS ((sbitmap, int));
674extern int propagate_block	PARAMS ((basic_block, regset, regset, regset,
675					 int));
676
677struct propagate_block_info;
678extern rtx propagate_one_insn	PARAMS ((struct propagate_block_info *, rtx));
679extern struct propagate_block_info *init_propagate_block_info
680  PARAMS ((basic_block, regset, regset, regset, int));
681extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
682
683/* In lcm.c */
684extern struct edge_list *pre_edge_lcm	PARAMS ((FILE *, int, sbitmap *,
685						 sbitmap *, sbitmap *,
686						 sbitmap *, sbitmap **,
687						 sbitmap **));
688extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
689						   sbitmap *, sbitmap *,
690						   sbitmap *, sbitmap **,
691						   sbitmap **));
692extern void compute_available		PARAMS ((sbitmap *, sbitmap *,
693						 sbitmap *, sbitmap *));
694extern int optimize_mode_switching	PARAMS ((FILE *));
695
696/* In emit-rtl.c.  */
697extern rtx emit_block_insn_after	PARAMS ((rtx, rtx, basic_block));
698extern rtx emit_block_insn_before	PARAMS ((rtx, rtx, basic_block));
699
700/* In predict.c */
701extern void estimate_probability        PARAMS ((struct loops *));
702extern void note_prediction_to_br_prob	PARAMS ((void));
703extern void expected_value_to_br_prob	PARAMS ((void));
704extern void note_prediction_to_br_prob	PARAMS ((void));
705extern bool maybe_hot_bb_p		PARAMS ((basic_block));
706extern bool probably_cold_bb_p		PARAMS ((basic_block));
707extern bool probably_never_executed_bb_p PARAMS ((basic_block));
708
709/* In flow.c */
710extern void init_flow                   PARAMS ((void));
711extern void reorder_basic_blocks	PARAMS ((void));
712extern void dump_bb			PARAMS ((basic_block, FILE *));
713extern void debug_bb			PARAMS ((basic_block));
714extern void debug_bb_n			PARAMS ((int));
715extern void dump_regset			PARAMS ((regset, FILE *));
716extern void debug_regset		PARAMS ((regset));
717extern void allocate_reg_life_data      PARAMS ((void));
718extern void allocate_bb_life_data	PARAMS ((void));
719extern void expunge_block		PARAMS ((basic_block));
720extern void link_block			PARAMS ((basic_block, basic_block));
721extern void unlink_block		PARAMS ((basic_block));
722extern void compact_blocks		PARAMS ((void));
723extern basic_block alloc_block		PARAMS ((void));
724extern void find_unreachable_blocks	PARAMS ((void));
725extern int delete_noop_moves		PARAMS ((rtx));
726extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
727extern basic_block force_nonfallthru	PARAMS ((edge));
728extern bool redirect_edge_and_branch	PARAMS ((edge, basic_block));
729extern rtx block_label			PARAMS ((basic_block));
730extern bool forwarder_block_p		PARAMS ((basic_block));
731extern bool purge_all_dead_edges	PARAMS ((int));
732extern bool purge_dead_edges		PARAMS ((basic_block));
733extern void find_sub_basic_blocks	PARAMS ((basic_block));
734extern void find_many_sub_basic_blocks	PARAMS ((sbitmap));
735extern bool can_fallthru		PARAMS ((basic_block, basic_block));
736extern void flow_nodes_print		PARAMS ((const char *, const sbitmap,
737						 FILE *));
738extern void flow_edge_list_print	PARAMS ((const char *, const edge *,
739						 int, FILE *));
740extern void alloc_aux_for_block		PARAMS ((basic_block, int));
741extern void alloc_aux_for_blocks	PARAMS ((int));
742extern void clear_aux_for_blocks	PARAMS ((void));
743extern void free_aux_for_blocks		PARAMS ((void));
744extern void alloc_aux_for_edge		PARAMS ((edge, int));
745extern void alloc_aux_for_edges		PARAMS ((int));
746extern void clear_aux_for_edges		PARAMS ((void));
747extern void free_aux_for_edges		PARAMS ((void));
748
749/* This function is always defined so it can be called from the
750   debugger, and it is declared extern so we don't get warnings about
751   it being unused.  */
752extern void verify_flow_info		PARAMS ((void));
753extern bool flow_loop_outside_edge_p	PARAMS ((const struct loop *, edge));
754extern bool flow_loop_nested_p		PARAMS ((const struct loop *,
755						 const struct loop *));
756extern bool flow_bb_inside_loop_p	PARAMS ((const struct loop *,
757						 const basic_block));
758extern basic_block *get_loop_body       PARAMS ((const struct loop *));
759extern int dfs_enumerate_from           PARAMS ((basic_block, int,
760				         bool (*)(basic_block, void *),
761					 basic_block *, int, void *));
762
763extern edge loop_preheader_edge PARAMS ((struct loop *));
764extern edge loop_latch_edge PARAMS ((struct loop *));
765
766extern void add_bb_to_loop PARAMS ((basic_block, struct loop *));
767extern void remove_bb_from_loops PARAMS ((basic_block));
768extern struct loop * find_common_loop PARAMS ((struct loop *, struct loop *));
769
770extern void verify_loop_structure PARAMS ((struct loops *, int));
771#define VLS_EXPECT_PREHEADERS 1
772#define VLS_EXPECT_SIMPLE_LATCHES 2
773
774typedef struct conflict_graph_def *conflict_graph;
775
776/* Callback function when enumerating conflicts.  The arguments are
777   the smaller and larger regno in the conflict.  Returns zero if
778   enumeration is to continue, nonzero to halt enumeration.  */
779typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
780
781
782/* Prototypes of operations on conflict graphs.  */
783
784extern conflict_graph conflict_graph_new
785                                        PARAMS ((int));
786extern void conflict_graph_delete       PARAMS ((conflict_graph));
787extern int conflict_graph_add           PARAMS ((conflict_graph,
788						 int, int));
789extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
790						 int, int));
791extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
792						 conflict_graph_enum_fn,
793						 void *));
794extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
795						 int));
796extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
797extern conflict_graph conflict_graph_compute
798                                        PARAMS ((regset,
799						 partition));
800extern bool mark_dfs_back_edges		PARAMS ((void));
801extern void set_edge_can_fallthru_flag	PARAMS ((void));
802extern void update_br_prob_note		PARAMS ((basic_block));
803extern void fixup_abnormal_edges	PARAMS ((void));
804extern bool can_hoist_insn_p		PARAMS ((rtx, rtx, regset));
805extern rtx hoist_insn_after		PARAMS ((rtx, rtx, rtx, rtx));
806extern rtx hoist_insn_to_edge		PARAMS ((rtx, edge, rtx, rtx));
807extern bool control_flow_insn_p		PARAMS ((rtx));
808
809/* In dominance.c */
810
811enum cdi_direction
812{
813  CDI_DOMINATORS,
814  CDI_POST_DOMINATORS
815};
816
817extern dominance_info calculate_dominance_info	PARAMS ((enum cdi_direction));
818extern void free_dominance_info			PARAMS ((dominance_info));
819extern basic_block nearest_common_dominator	PARAMS ((dominance_info,
820						 basic_block, basic_block));
821extern void set_immediate_dominator	PARAMS ((dominance_info,
822						 basic_block, basic_block));
823extern basic_block get_immediate_dominator	PARAMS ((dominance_info,
824						 basic_block));
825extern bool dominated_by_p	PARAMS ((dominance_info, basic_block, basic_block));
826extern int get_dominated_by PARAMS ((dominance_info, basic_block, basic_block **));
827extern void add_to_dominance_info PARAMS ((dominance_info, basic_block));
828extern void delete_from_dominance_info PARAMS ((dominance_info, basic_block));
829basic_block recount_dominator PARAMS ((dominance_info, basic_block));
830extern void redirect_immediate_dominators PARAMS ((dominance_info, basic_block,
831						 basic_block));
832void iterate_fix_dominators PARAMS ((dominance_info, basic_block *, int));
833extern void verify_dominators PARAMS ((dominance_info));
834#endif /* GCC_BASIC_BLOCK_H */
835