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1 /* Define control and data flow tables, and regsets.
2 Copyright (C) 1987, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 #ifndef _BASIC_BLOCK_H
22 #define _BASIC_BLOCK_H 1
24 #include "bitmap.h"
25 #include "sbitmap.h"
26 #include "varray.h"
27 #include "partition.h"
29 /* Head of register set linked list. */
30 typedef bitmap_head regset_head;
31 /* A pointer to a regset_head. */
32 typedef bitmap regset;
34 /* Initialize a new regset. */
35 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD)
37 /* Clear a register set by freeing up the linked list. */
38 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
40 /* Copy a register set to another register set. */
41 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
43 /* Compare two register sets. */
44 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
46 /* `and' a register set with a second register set. */
47 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
49 /* `and' the complement of a register set with a register set. */
50 #define AND_COMPL_REG_SET(TO, FROM) \
51 bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
53 /* Inclusive or a register set with a second register set. */
54 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
56 /* Exclusive or a register set with a second register set. */
57 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
59 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2. */
60 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
61 bitmap_ior_and_compl (TO, FROM1, FROM2)
63 /* Clear a single register in a register set. */
64 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
66 /* Set a single register in a register set. */
67 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
69 /* Return true if a register is set in a register set. */
70 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
72 /* Copy the hard registers in a register set to the hard register set. */
73 extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
74 #define REG_SET_TO_HARD_REG_SET(TO, FROM) \
75 do { \
76 CLEAR_HARD_REG_SET (TO); \
77 reg_set_to_hard_reg_set (&TO, FROM); \
78 } while (0)
80 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
81 register number and executing CODE for all registers that are set. */
82 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE) \
83 EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
85 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
86 REGNUM to the register number and executing CODE for all registers that are
87 set in the first regset and not set in the second. */
88 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
89 EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
91 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
92 REGNUM to the register number and executing CODE for all registers that are
93 set in both regsets. */
94 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
95 EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
97 /* Allocate a register set with oballoc. */
98 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
100 /* Initialize a register set. Returns the new register set. */
101 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD)
103 /* Do any cleanup needed on a regset when it is no longer used. */
104 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
106 /* Do any one-time initializations needed for regsets. */
107 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
109 /* Grow any tables needed when the number of registers is calculated
110 or extended. For the linked list allocation, nothing needs to
111 be done, other than zero the statistics on the first allocation. */
112 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
114 /* Control flow edge information. */
115 typedef struct edge_def {
116 /* Links through the predecessor and successor lists. */
117 struct edge_def *pred_next, *succ_next;
119 /* The two blocks at the ends of the edge. */
120 struct basic_block_def *src, *dest;
122 /* Instructions queued on the edge. */
123 rtx insns;
125 /* Auxiliary info specific to a pass. */
126 void *aux;
128 int flags; /* see EDGE_* below */
129 int probability; /* biased by REG_BR_PROB_BASE */
130 int count; /* Expected number of executions calculated
131 in profile.c */
132 } *edge;
134 #define EDGE_FALLTHRU 1
135 #define EDGE_CRITICAL 2
136 #define EDGE_ABNORMAL 4
137 #define EDGE_ABNORMAL_CALL 8
138 #define EDGE_EH 16
139 #define EDGE_FAKE 32
141 #define EDGE_COMPLEX (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
144 /* Basic blocks need not start with a label nor end with a jump insn.
145 For example, a previous basic block may just "conditionally fall"
146 into the succeeding basic block, and the last basic block need not
147 end with a jump insn. Block 0 is a descendant of the entry block.
149 A basic block beginning with two labels cannot have notes between
150 the labels.
152 Data for jump tables are stored in jump_insns that occur in no
153 basic block even though these insns can follow or precede insns in
154 basic blocks. */
156 /* Basic block information indexed by block number. */
157 typedef struct basic_block_def {
158 /* The first and last insns of the block. */
159 rtx head, end;
161 /* The edges into and out of the block. */
162 edge pred, succ;
164 /* Liveness info. Note that in SSA form, global_live_at_start does
165 not reflect the use of regs in phi functions, since the liveness
166 of these regs may depend on which edge was taken into the block. */
167 regset local_set;
168 regset cond_local_set;
169 regset global_live_at_start;
170 regset global_live_at_end;
172 /* Auxiliary info specific to a pass. */
173 void *aux;
175 /* The index of this block. */
176 int index;
178 /* The loop depth of this block. */
179 int loop_depth;
181 /* Expected number of executions: calculated in profile.c. */
182 int count;
183 } *basic_block;
185 /* Number of basic blocks in the current function. */
187 extern int n_basic_blocks;
189 /* Number of edges in the current function. */
191 extern int n_edges;
193 /* Index by basic block number, get basic block struct info. */
195 extern varray_type basic_block_info;
197 #define BASIC_BLOCK(N) (VARRAY_BB (basic_block_info, (N)))
199 /* What registers are live at the setjmp call. */
201 extern regset regs_live_at_setjmp;
203 /* Indexed by n, gives number of basic block that (REG n) is used in.
204 If the value is REG_BLOCK_GLOBAL (-2),
205 it means (REG n) is used in more than one basic block.
206 REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
207 This information remains valid for the rest of the compilation
208 of the current function; it is used to control register allocation. */
210 #define REG_BLOCK_UNKNOWN -1
211 #define REG_BLOCK_GLOBAL -2
213 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
215 /* Stuff for recording basic block info. */
217 #define BLOCK_HEAD(B) (BASIC_BLOCK (B)->head)
218 #define BLOCK_END(B) (BASIC_BLOCK (B)->end)
220 /* Special block numbers [markers] for entry and exit. */
221 #define ENTRY_BLOCK (-1)
222 #define EXIT_BLOCK (-2)
224 /* Special block number not valid for any block. */
225 #define INVALID_BLOCK (-3)
227 /* Similarly, block pointers for the edge list. */
228 extern struct basic_block_def entry_exit_blocks[2];
229 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
230 #define EXIT_BLOCK_PTR (&entry_exit_blocks[1])
232 extern varray_type basic_block_for_insn;
233 #define BLOCK_FOR_INSN(INSN) VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
234 #define BLOCK_NUM(INSN) (BLOCK_FOR_INSN (INSN)->index + 0)
236 extern void compute_bb_for_insn PARAMS ((int));
237 extern void update_bb_for_insn PARAMS ((basic_block));
238 extern void set_block_for_insn PARAMS ((rtx, basic_block));
239 extern void set_block_num PARAMS ((rtx, int));
241 extern void free_basic_block_vars PARAMS ((int));
243 extern edge split_block PARAMS ((basic_block, rtx));
244 extern basic_block split_edge PARAMS ((edge));
245 extern void insert_insn_on_edge PARAMS ((rtx, edge));
246 extern void commit_edge_insertions PARAMS ((void));
247 extern void remove_fake_edges PARAMS ((void));
248 extern void add_noreturn_fake_exit_edges PARAMS ((void));
249 extern void connect_infinite_loops_to_exit PARAMS ((void));
250 extern int flow_call_edges_add PARAMS ((sbitmap));
251 extern rtx flow_delete_insn PARAMS ((rtx));
252 extern void flow_delete_insn_chain PARAMS ((rtx, rtx));
253 extern void make_edge PARAMS ((sbitmap *, basic_block,
254 basic_block, int));
255 extern void remove_edge PARAMS ((edge));
256 extern void redirect_edge_succ PARAMS ((edge, basic_block));
257 extern void redirect_edge_pred PARAMS ((edge, basic_block));
258 extern void create_basic_block PARAMS ((int, rtx, rtx, rtx));
259 extern int flow_delete_block PARAMS ((basic_block));
260 extern void merge_blocks_nomove PARAMS ((basic_block, basic_block));
261 extern void tidy_fallthru_edge PARAMS ((edge, basic_block,
262 basic_block));
264 /* Structure to hold information for each natural loop. */
265 struct loop
267 /* Index into loops array. */
268 int num;
270 /* Basic block of loop header. */
271 basic_block header;
273 /* Basic block of loop latch. */
274 basic_block latch;
276 /* Basic block of loop pre-header or NULL if it does not exist. */
277 basic_block pre_header;
279 /* Array of edges along the pre-header extended basic block trace.
280 The source of the first edge is the root node of pre-header
281 extended basic block, if it exists. */
282 edge *pre_header_edges;
284 /* Number of edges along the pre_header extended basic block trace. */
285 int num_pre_header_edges;
287 /* The first block in the loop. This is not necessarily the same as
288 the loop header. */
289 basic_block first;
291 /* The last block in the loop. This is not necessarily the same as
292 the loop latch. */
293 basic_block last;
295 /* Bitmap of blocks contained within the loop. */
296 sbitmap nodes;
298 /* Number of blocks contained within the loop. */
299 int num_nodes;
301 /* Array of edges that enter the loop. */
302 edge *entry_edges;
304 /* Number of edges that enter the loop. */
305 int num_entries;
307 /* Array of edges that exit the loop. */
308 edge *exit_edges;
310 /* Number of edges that exit the loop. */
311 int num_exits;
313 /* Bitmap of blocks that dominate all exits of the loop. */
314 sbitmap exits_doms;
316 /* The loop nesting depth. */
317 int depth;
319 /* The height of the loop (enclosed loop levels) within the loop
320 hierarchy tree. */
321 int level;
323 /* The outer (parent) loop or NULL if outermost loop. */
324 struct loop *outer;
326 /* The first inner (child) loop or NULL if innermost loop. */
327 struct loop *inner;
329 /* Link to the next (sibling) loop. */
330 struct loop *next;
332 /* Non-zero if the loop shares a header with another loop. */
333 int shared;
335 /* Non-zero if the loop is invalid (e.g., contains setjmp.). */
336 int invalid;
338 /* Auxiliary info specific to a pass. */
339 void *aux;
341 /* The following are currently used by loop.c but they are likely to
342 disappear as loop.c is converted to use the CFG. */
344 /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP. */
345 rtx vtop;
347 /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
348 A continue statement will generate a branch to NEXT_INSN (cont). */
349 rtx cont;
351 /* The dominator of cont. */
352 rtx cont_dominator;
354 /* The NOTE_INSN_LOOP_BEG. */
355 rtx start;
357 /* The NOTE_INSN_LOOP_END. */
358 rtx end;
360 /* For a rotated loop that is entered near the bottom,
361 this is the label at the top. Otherwise it is zero. */
362 rtx top;
364 /* Place in the loop where control enters. */
365 rtx scan_start;
367 /* The position where to sink insns out of the loop. */
368 rtx sink;
370 /* List of all LABEL_REFs which refer to code labels outside the
371 loop. Used by routines that need to know all loop exits, such as
372 final_biv_value and final_giv_value.
374 This does not include loop exits due to return instructions.
375 This is because all bivs and givs are pseudos, and hence must be
376 dead after a return, so the presense of a return does not affect
377 any of the optimizations that use this info. It is simpler to
378 just not include return instructions on this list. */
379 rtx exit_labels;
381 /* The number of LABEL_REFs on exit_labels for this loop and all
382 loops nested inside it. */
383 int exit_count;
387 /* Structure to hold CFG information about natural loops within a function. */
388 struct loops
390 /* Number of natural loops in the function. */
391 int num;
393 /* Maxium nested loop level in the function. */
394 int levels;
396 /* Array of natural loop descriptors (scanning this array in reverse order
397 will find the inner loops before their enclosing outer loops). */
398 struct loop *array;
400 /* Pointer to root of loop heirachy tree. */
401 struct loop *tree;
403 /* Information derived from the CFG. */
404 struct cfg
406 /* The bitmap vector of dominators or NULL if not computed. */
407 sbitmap *dom;
409 /* The ordering of the basic blocks in a depth first search. */
410 int *dfs_order;
412 /* The reverse completion ordering of the basic blocks found in a
413 depth first search. */
414 int *rc_order;
415 } cfg;
417 /* Headers shared by multiple loops that should be merged. */
418 sbitmap shared_headers;
421 extern int flow_loops_find PARAMS ((struct loops *, int flags));
422 extern int flow_loops_update PARAMS ((struct loops *, int flags));
423 extern void flow_loops_free PARAMS ((struct loops *));
424 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
425 void (*)(const struct loop *,
426 FILE *, int), int));
427 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
428 void (*)(const struct loop *,
429 FILE *, int), int));
430 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
432 /* This structure maintains an edge list vector. */
433 struct edge_list
435 int num_blocks;
436 int num_edges;
437 edge *index_to_edge;
440 /* This is the value which indicates no edge is present. */
441 #define EDGE_INDEX_NO_EDGE -1
443 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
444 if there is no edge between the 2 basic blocks. */
445 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
447 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
448 block which is either the pred or succ end of the indexed edge. */
449 #define INDEX_EDGE_PRED_BB(el, index) ((el)->index_to_edge[(index)]->src)
450 #define INDEX_EDGE_SUCC_BB(el, index) ((el)->index_to_edge[(index)]->dest)
452 /* INDEX_EDGE returns a pointer to the edge. */
453 #define INDEX_EDGE(el, index) ((el)->index_to_edge[(index)])
455 /* Number of edges in the compressed edge list. */
456 #define NUM_EDGES(el) ((el)->num_edges)
458 struct edge_list * create_edge_list PARAMS ((void));
459 void free_edge_list PARAMS ((struct edge_list *));
460 void print_edge_list PARAMS ((FILE *, struct edge_list *));
461 void verify_edge_list PARAMS ((FILE *, struct edge_list *));
462 int find_edge_index PARAMS ((struct edge_list *,
463 basic_block, basic_block));
466 enum update_life_extent
468 UPDATE_LIFE_LOCAL = 0,
469 UPDATE_LIFE_GLOBAL = 1,
470 UPDATE_LIFE_GLOBAL_RM_NOTES = 2
473 /* Flags for life_analysis and update_life_info. */
475 #define PROP_DEATH_NOTES 1 /* Create DEAD and UNUSED notes. */
476 #define PROP_LOG_LINKS 2 /* Create LOG_LINKS. */
477 #define PROP_REG_INFO 4 /* Update regs_ever_live et al. */
478 #define PROP_KILL_DEAD_CODE 8 /* Remove dead code. */
479 #define PROP_SCAN_DEAD_CODE 16 /* Scan for dead code. */
480 #define PROP_AUTOINC 32 /* Create autoinc mem references. */
481 #define PROP_FINAL 63 /* All of the above. */
483 /* Flags for loop discovery. */
485 #define LOOP_TREE 1 /* Build loop hierarchy tree. */
486 #define LOOP_PRE_HEADER 2 /* Analyse loop pre-header. */
487 #define LOOP_ENTRY_EDGES 4 /* Find entry edges. */
488 #define LOOP_EXIT_EDGES 8 /* Find exit edges. */
489 #define LOOP_EDGES (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
490 #define LOOP_EXITS_DOMS 16 /* Find nodes that dom. all exits. */
491 #define LOOP_ALL 31 /* All of the above */
493 extern void life_analysis PARAMS ((rtx, FILE *, int));
494 extern void update_life_info PARAMS ((sbitmap, enum update_life_extent,
495 int));
496 extern int count_or_remove_death_notes PARAMS ((sbitmap, int));
497 extern void propagate_block PARAMS ((basic_block, regset, regset, regset,
498 int));
500 struct propagate_block_info;
501 extern rtx propagate_one_insn PARAMS ((struct propagate_block_info *, rtx));
502 extern struct propagate_block_info *init_propagate_block_info
503 PARAMS ((basic_block, regset, regset, regset, int));
504 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
506 /* In lcm.c */
507 extern struct edge_list *pre_edge_lcm PARAMS ((FILE *, int, sbitmap *,
508 sbitmap *, sbitmap *,
509 sbitmap *, sbitmap **,
510 sbitmap **));
511 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
512 sbitmap *, sbitmap *,
513 sbitmap *, sbitmap **,
514 sbitmap **));
515 extern void compute_available PARAMS ((sbitmap *, sbitmap *,
516 sbitmap *, sbitmap *));
517 extern int optimize_mode_switching PARAMS ((FILE *));
519 /* In emit-rtl.c. */
520 extern rtx emit_block_insn_after PARAMS ((rtx, rtx, basic_block));
521 extern rtx emit_block_insn_before PARAMS ((rtx, rtx, basic_block));
523 /* In predict.c */
524 extern void estimate_probability PARAMS ((struct loops *));
525 extern void expected_value_to_br_prob PARAMS ((void));
527 /* In flow.c */
528 extern void init_flow PARAMS ((void));
529 extern void reorder_basic_blocks PARAMS ((void));
530 extern void dump_bb PARAMS ((basic_block, FILE *));
531 extern void debug_bb PARAMS ((basic_block));
532 extern void debug_bb_n PARAMS ((int));
533 extern void dump_regset PARAMS ((regset, FILE *));
534 extern void debug_regset PARAMS ((regset));
535 extern void allocate_reg_life_data PARAMS ((void));
537 /* This function is always defined so it can be called from the
538 debugger, and it is declared extern so we don't get warnings about
539 it being unused. */
540 extern void verify_flow_info PARAMS ((void));
541 extern int flow_loop_outside_edge_p PARAMS ((const struct loop *, edge));
543 typedef struct conflict_graph_def *conflict_graph;
545 /* Callback function when enumerating conflicts. The arguments are
546 the smaller and larger regno in the conflict. Returns zero if
547 enumeration is to continue, non-zero to halt enumeration. */
548 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
551 /* Prototypes of operations on conflict graphs. */
553 extern conflict_graph conflict_graph_new
554 PARAMS ((int));
555 extern void conflict_graph_delete PARAMS ((conflict_graph));
556 extern int conflict_graph_add PARAMS ((conflict_graph,
557 int, int));
558 extern int conflict_graph_conflict_p PARAMS ((conflict_graph,
559 int, int));
560 extern void conflict_graph_enum PARAMS ((conflict_graph, int,
561 conflict_graph_enum_fn,
562 void *));
563 extern void conflict_graph_merge_regs PARAMS ((conflict_graph, int,
564 int));
565 extern void conflict_graph_print PARAMS ((conflict_graph, FILE*));
566 extern conflict_graph conflict_graph_compute
567 PARAMS ((regset,
568 partition));
570 /* In dominance.c */
572 enum cdi_direction
574 CDI_DOMINATORS,
575 CDI_POST_DOMINATORS
578 extern void calculate_dominance_info PARAMS ((int *, sbitmap *,
579 enum cdi_direction));
581 #endif /* _BASIC_BLOCK_H */