xref: /openbsd/gnu/usr.bin/gcc/gcc/basic-block.h (revision c87b03e5)
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 
5 This file is part of GCC.
6 
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
10 version.
11 
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
15 for more details.
16 
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
20 02111-1307, 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.  */
32 typedef bitmap_head regset_head;
33 /* A pointer to a regset_head.  */
34 typedef 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.  */
75 extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
76 #define REG_SET_TO_HARD_REG_SET(TO, FROM)				\
77 do {									\
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.  */
117 typedef HOST_WIDEST_INT gcov_type;
118 
119 /* Control flow edge information.  */
120 typedef 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.  */
179 typedef 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 
242 extern int n_basic_blocks;
243 
244 /* First free basic block number.  */
245 
246 extern int last_basic_block;
247 
248 /* Number of edges in the current function.  */
249 
250 extern int n_edges;
251 
252 /* Index by basic block number, get basic block struct info.  */
253 
254 extern 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 
276 extern regset regs_live_at_setjmp;
277 
278 /* Special labels found during CFG build.  */
279 
280 extern GTY(()) rtx label_value_list;
281 extern GTY(()) rtx tail_recursion_label_list;
282 
283 extern 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.  */
313 extern 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 
320 extern void compute_bb_for_insn		PARAMS ((void));
321 extern void free_bb_for_insn		PARAMS ((void));
322 extern void update_bb_for_insn		PARAMS ((basic_block));
323 
324 extern void free_basic_block_vars	PARAMS ((int));
325 
326 extern edge split_block			PARAMS ((basic_block, rtx));
327 extern basic_block split_edge		PARAMS ((edge));
328 extern void insert_insn_on_edge		PARAMS ((rtx, edge));
329 
330 extern void commit_edge_insertions	PARAMS ((void));
331 extern void commit_edge_insertions_watch_calls	PARAMS ((void));
332 
333 extern void remove_fake_edges		PARAMS ((void));
334 extern void add_noreturn_fake_exit_edges	PARAMS ((void));
335 extern void connect_infinite_loops_to_exit	PARAMS ((void));
336 extern int flow_call_edges_add		PARAMS ((sbitmap));
337 extern edge cached_make_edge		PARAMS ((sbitmap *, basic_block,
338 						 basic_block, int));
339 extern edge unchecked_make_edge		PARAMS ((basic_block,
340 						 basic_block, int));
341 extern edge make_edge			PARAMS ((basic_block,
342 						 basic_block, int));
343 extern edge make_single_succ_edge	PARAMS ((basic_block,
344 						 basic_block, int));
345 extern void remove_edge			PARAMS ((edge));
346 extern void redirect_edge_succ		PARAMS ((edge, basic_block));
347 extern edge redirect_edge_succ_nodup	PARAMS ((edge, basic_block));
348 extern void redirect_edge_pred		PARAMS ((edge, basic_block));
349 extern basic_block create_basic_block_structure PARAMS ((rtx, rtx, rtx, basic_block));
350 extern basic_block create_basic_block	PARAMS ((rtx, rtx, basic_block));
351 extern int flow_delete_block		PARAMS ((basic_block));
352 extern int flow_delete_block_noexpunge	PARAMS ((basic_block));
353 extern void clear_bb_flags		PARAMS ((void));
354 extern void merge_blocks_nomove		PARAMS ((basic_block, basic_block));
355 extern void tidy_fallthru_edge		PARAMS ((edge, basic_block,
356 						 basic_block));
357 extern void tidy_fallthru_edges		PARAMS ((void));
358 extern void flow_reverse_top_sort_order_compute	PARAMS ((int *));
359 extern int flow_depth_first_order_compute	PARAMS ((int *, int *));
360 extern void flow_preorder_transversal_compute	PARAMS ((int *));
361 extern void dump_edge_info		PARAMS ((FILE *, edge, int));
362 extern void clear_edges			PARAMS ((void));
363 extern void mark_critical_edges		PARAMS ((void));
364 extern rtx first_insn_after_basic_block_note	PARAMS ((basic_block));
365 
366 /* Dominator information for basic blocks.  */
367 
368 typedef struct dominance_info *dominance_info;
369 
370 /* Structure to hold information for each natural loop.  */
371 struct 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.  */
491 struct 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 
534 typedef 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 
556 extern int flow_loops_find PARAMS ((struct loops *, int flags));
557 extern int flow_loops_update PARAMS ((struct loops *, int flags));
558 extern void flow_loops_free PARAMS ((struct loops *));
559 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
560 				     void (*)(const struct loop *,
561 					      FILE *, int), int));
562 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
563 				    void (*)(const struct loop *,
564 					     FILE *, int), int));
565 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
566 extern void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *));
567 extern void flow_loop_tree_node_remove PARAMS ((struct loop *));
568 
569 /* This structure maintains an edge list vector.  */
570 struct 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 
613 struct edge_list * create_edge_list	PARAMS ((void));
614 void free_edge_list			PARAMS ((struct edge_list *));
615 void print_edge_list			PARAMS ((FILE *, struct edge_list *));
616 void verify_edge_list			PARAMS ((FILE *, struct edge_list *));
617 int find_edge_index			PARAMS ((struct edge_list *,
618 						 basic_block, basic_block));
619 
620 
621 enum 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 
668 extern void life_analysis	PARAMS ((rtx, FILE *, int));
669 extern int update_life_info	PARAMS ((sbitmap, enum update_life_extent,
670 					 int));
671 extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
672 						      int));
673 extern int count_or_remove_death_notes	PARAMS ((sbitmap, int));
674 extern int propagate_block	PARAMS ((basic_block, regset, regset, regset,
675 					 int));
676 
677 struct propagate_block_info;
678 extern rtx propagate_one_insn	PARAMS ((struct propagate_block_info *, rtx));
679 extern struct propagate_block_info *init_propagate_block_info
680   PARAMS ((basic_block, regset, regset, regset, int));
681 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
682 
683 /* In lcm.c */
684 extern struct edge_list *pre_edge_lcm	PARAMS ((FILE *, int, sbitmap *,
685 						 sbitmap *, sbitmap *,
686 						 sbitmap *, sbitmap **,
687 						 sbitmap **));
688 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
689 						   sbitmap *, sbitmap *,
690 						   sbitmap *, sbitmap **,
691 						   sbitmap **));
692 extern void compute_available		PARAMS ((sbitmap *, sbitmap *,
693 						 sbitmap *, sbitmap *));
694 extern int optimize_mode_switching	PARAMS ((FILE *));
695 
696 /* In emit-rtl.c.  */
697 extern rtx emit_block_insn_after	PARAMS ((rtx, rtx, basic_block));
698 extern rtx emit_block_insn_before	PARAMS ((rtx, rtx, basic_block));
699 
700 /* In predict.c */
701 extern void estimate_probability        PARAMS ((struct loops *));
702 extern void note_prediction_to_br_prob	PARAMS ((void));
703 extern void expected_value_to_br_prob	PARAMS ((void));
704 extern void note_prediction_to_br_prob	PARAMS ((void));
705 extern bool maybe_hot_bb_p		PARAMS ((basic_block));
706 extern bool probably_cold_bb_p		PARAMS ((basic_block));
707 extern bool probably_never_executed_bb_p PARAMS ((basic_block));
708 
709 /* In flow.c */
710 extern void init_flow                   PARAMS ((void));
711 extern void reorder_basic_blocks	PARAMS ((void));
712 extern void dump_bb			PARAMS ((basic_block, FILE *));
713 extern void debug_bb			PARAMS ((basic_block));
714 extern void debug_bb_n			PARAMS ((int));
715 extern void dump_regset			PARAMS ((regset, FILE *));
716 extern void debug_regset		PARAMS ((regset));
717 extern void allocate_reg_life_data      PARAMS ((void));
718 extern void allocate_bb_life_data	PARAMS ((void));
719 extern void expunge_block		PARAMS ((basic_block));
720 extern void link_block			PARAMS ((basic_block, basic_block));
721 extern void unlink_block		PARAMS ((basic_block));
722 extern void compact_blocks		PARAMS ((void));
723 extern basic_block alloc_block		PARAMS ((void));
724 extern void find_unreachable_blocks	PARAMS ((void));
725 extern int delete_noop_moves		PARAMS ((rtx));
726 extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
727 extern basic_block force_nonfallthru	PARAMS ((edge));
728 extern bool redirect_edge_and_branch	PARAMS ((edge, basic_block));
729 extern rtx block_label			PARAMS ((basic_block));
730 extern bool forwarder_block_p		PARAMS ((basic_block));
731 extern bool purge_all_dead_edges	PARAMS ((int));
732 extern bool purge_dead_edges		PARAMS ((basic_block));
733 extern void find_sub_basic_blocks	PARAMS ((basic_block));
734 extern void find_many_sub_basic_blocks	PARAMS ((sbitmap));
735 extern bool can_fallthru		PARAMS ((basic_block, basic_block));
736 extern void flow_nodes_print		PARAMS ((const char *, const sbitmap,
737 						 FILE *));
738 extern void flow_edge_list_print	PARAMS ((const char *, const edge *,
739 						 int, FILE *));
740 extern void alloc_aux_for_block		PARAMS ((basic_block, int));
741 extern void alloc_aux_for_blocks	PARAMS ((int));
742 extern void clear_aux_for_blocks	PARAMS ((void));
743 extern void free_aux_for_blocks		PARAMS ((void));
744 extern void alloc_aux_for_edge		PARAMS ((edge, int));
745 extern void alloc_aux_for_edges		PARAMS ((int));
746 extern void clear_aux_for_edges		PARAMS ((void));
747 extern 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.  */
752 extern void verify_flow_info		PARAMS ((void));
753 extern bool flow_loop_outside_edge_p	PARAMS ((const struct loop *, edge));
754 extern bool flow_loop_nested_p		PARAMS ((const struct loop *,
755 						 const struct loop *));
756 extern bool flow_bb_inside_loop_p	PARAMS ((const struct loop *,
757 						 const basic_block));
758 extern basic_block *get_loop_body       PARAMS ((const struct loop *));
759 extern int dfs_enumerate_from           PARAMS ((basic_block, int,
760 				         bool (*)(basic_block, void *),
761 					 basic_block *, int, void *));
762 
763 extern edge loop_preheader_edge PARAMS ((struct loop *));
764 extern edge loop_latch_edge PARAMS ((struct loop *));
765 
766 extern void add_bb_to_loop PARAMS ((basic_block, struct loop *));
767 extern void remove_bb_from_loops PARAMS ((basic_block));
768 extern struct loop * find_common_loop PARAMS ((struct loop *, struct loop *));
769 
770 extern void verify_loop_structure PARAMS ((struct loops *, int));
771 #define VLS_EXPECT_PREHEADERS 1
772 #define VLS_EXPECT_SIMPLE_LATCHES 2
773 
774 typedef 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.  */
779 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
780 
781 
782 /* Prototypes of operations on conflict graphs.  */
783 
784 extern conflict_graph conflict_graph_new
785                                         PARAMS ((int));
786 extern void conflict_graph_delete       PARAMS ((conflict_graph));
787 extern int conflict_graph_add           PARAMS ((conflict_graph,
788 						 int, int));
789 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
790 						 int, int));
791 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
792 						 conflict_graph_enum_fn,
793 						 void *));
794 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
795 						 int));
796 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
797 extern conflict_graph conflict_graph_compute
798                                         PARAMS ((regset,
799 						 partition));
800 extern bool mark_dfs_back_edges		PARAMS ((void));
801 extern void set_edge_can_fallthru_flag	PARAMS ((void));
802 extern void update_br_prob_note		PARAMS ((basic_block));
803 extern void fixup_abnormal_edges	PARAMS ((void));
804 extern bool can_hoist_insn_p		PARAMS ((rtx, rtx, regset));
805 extern rtx hoist_insn_after		PARAMS ((rtx, rtx, rtx, rtx));
806 extern rtx hoist_insn_to_edge		PARAMS ((rtx, edge, rtx, rtx));
807 extern bool control_flow_insn_p		PARAMS ((rtx));
808 
809 /* In dominance.c */
810 
811 enum cdi_direction
812 {
813   CDI_DOMINATORS,
814   CDI_POST_DOMINATORS
815 };
816 
817 extern dominance_info calculate_dominance_info	PARAMS ((enum cdi_direction));
818 extern void free_dominance_info			PARAMS ((dominance_info));
819 extern basic_block nearest_common_dominator	PARAMS ((dominance_info,
820 						 basic_block, basic_block));
821 extern void set_immediate_dominator	PARAMS ((dominance_info,
822 						 basic_block, basic_block));
823 extern basic_block get_immediate_dominator	PARAMS ((dominance_info,
824 						 basic_block));
825 extern bool dominated_by_p	PARAMS ((dominance_info, basic_block, basic_block));
826 extern int get_dominated_by PARAMS ((dominance_info, basic_block, basic_block **));
827 extern void add_to_dominance_info PARAMS ((dominance_info, basic_block));
828 extern void delete_from_dominance_info PARAMS ((dominance_info, basic_block));
829 basic_block recount_dominator PARAMS ((dominance_info, basic_block));
830 extern void redirect_immediate_dominators PARAMS ((dominance_info, basic_block,
831 						 basic_block));
832 void iterate_fix_dominators PARAMS ((dominance_info, basic_block *, int));
833 extern void verify_dominators PARAMS ((dominance_info));
834 #endif /* GCC_BASIC_BLOCK_H */
835