1 /* Define control and data flow tables, and regsets.
2 Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001 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)
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 GCC_BASIC_BLOCK_H
22 #define GCC_BASIC_BLOCK_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) \
76 CLEAR_HARD_REG_SET (TO); \
77 reg_set_to_hard_reg_set (&TO, FROM); \
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 /* Type we use to hold basic block counters. Should be at least 64bit. */
115 typedef HOST_WIDEST_INT gcov_type
;
117 /* Control flow edge information. */
118 typedef struct edge_def
{
119 /* Links through the predecessor and successor lists. */
120 struct edge_def
*pred_next
, *succ_next
;
122 /* The two blocks at the ends of the edge. */
123 struct basic_block_def
*src
, *dest
;
125 /* Instructions queued on the edge. */
128 /* Auxiliary info specific to a pass. */
131 int flags
; /* see EDGE_* below */
132 int probability
; /* biased by REG_BR_PROB_BASE */
133 gcov_type count
; /* Expected number of executions calculated
137 #define EDGE_FALLTHRU 1
138 #define EDGE_CRITICAL 2
139 #define EDGE_ABNORMAL 4
140 #define EDGE_ABNORMAL_CALL 8
144 #define EDGE_COMPLEX (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
147 /* A basic block is a sequence of instructions with only entry and
148 only one exit. If any one of the instructions are executed, they
149 will all be executed, and in sequence from first to last.
151 There may be COND_EXEC instructions in the basic block. The
152 COND_EXEC *instructions* will be executed -- but if the condition
153 is false the conditionally executed *expressions* will of course
154 not be executed. We don't consider the conditionally executed
155 expression (which might have side-effects) to be in a separate
156 basic block because the program counter will always be at the same
157 location after the COND_EXEC instruction, regardless of whether the
158 condition is true or not.
160 Basic blocks need not start with a label nor end with a jump insn.
161 For example, a previous basic block may just "conditionally fall"
162 into the succeeding basic block, and the last basic block need not
163 end with a jump insn. Block 0 is a descendant of the entry block.
165 A basic block beginning with two labels cannot have notes between
168 Data for jump tables are stored in jump_insns that occur in no
169 basic block even though these insns can follow or precede insns in
172 /* Basic block information indexed by block number. */
173 typedef struct basic_block_def
{
174 /* The first and last insns of the block. */
177 /* The edges into and out of the block. */
182 /* The registers that are modified within this in block. */
184 /* The registers that are conditionally modified within this block.
185 In other words, registers that are set only as part of a
187 regset cond_local_set
;
188 /* The registers that are live on entry to this block.
190 Note that in SSA form, global_live_at_start does not reflect the
191 use of regs in phi functions, since the liveness of these regs
192 may depend on which edge was taken into the block. */
193 regset global_live_at_start
;
194 /* The registers that are live on exit from this block. */
195 regset global_live_at_end
;
197 /* Auxiliary info specific to a pass. */
200 /* The index of this block. */
203 /* The loop depth of this block. */
206 /* Expected number of executions: calculated in profile.c. */
209 /* Expected frequency. Normalized to be in range 0 to BB_FREQ_MAX. */
213 #define BB_FREQ_MAX 10000
215 /* Number of basic blocks in the current function. */
217 extern int n_basic_blocks
;
219 /* Number of edges in the current function. */
223 /* Index by basic block number, get basic block struct info. */
225 extern varray_type basic_block_info
;
227 #define BASIC_BLOCK(N) (VARRAY_BB (basic_block_info, (N)))
229 /* What registers are live at the setjmp call. */
231 extern regset regs_live_at_setjmp
;
233 /* Indexed by n, gives number of basic block that (REG n) is used in.
234 If the value is REG_BLOCK_GLOBAL (-2),
235 it means (REG n) is used in more than one basic block.
236 REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
237 This information remains valid for the rest of the compilation
238 of the current function; it is used to control register allocation. */
240 #define REG_BLOCK_UNKNOWN -1
241 #define REG_BLOCK_GLOBAL -2
243 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
245 /* Stuff for recording basic block info. */
247 #define BLOCK_HEAD(B) (BASIC_BLOCK (B)->head)
248 #define BLOCK_END(B) (BASIC_BLOCK (B)->end)
250 /* Special block numbers [markers] for entry and exit. */
251 #define ENTRY_BLOCK (-1)
252 #define EXIT_BLOCK (-2)
254 /* Special block number not valid for any block. */
255 #define INVALID_BLOCK (-3)
257 /* Similarly, block pointers for the edge list. */
258 extern struct basic_block_def entry_exit_blocks
[2];
259 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
260 #define EXIT_BLOCK_PTR (&entry_exit_blocks[1])
262 extern varray_type basic_block_for_insn
;
263 #define BLOCK_FOR_INSN(INSN) VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
264 #define BLOCK_NUM(INSN) (BLOCK_FOR_INSN (INSN)->index + 0)
266 extern void compute_bb_for_insn
PARAMS ((int));
267 extern void update_bb_for_insn
PARAMS ((basic_block
));
268 extern void set_block_for_insn
PARAMS ((rtx
, basic_block
));
269 extern void set_block_for_new_insns
PARAMS ((rtx
, basic_block
));
271 extern void free_basic_block_vars
PARAMS ((int));
273 extern edge split_block
PARAMS ((basic_block
, rtx
));
274 extern basic_block split_edge
PARAMS ((edge
));
275 extern void insert_insn_on_edge
PARAMS ((rtx
, edge
));
276 extern void commit_edge_insertions
PARAMS ((void));
277 extern void remove_fake_edges
PARAMS ((void));
278 extern void add_noreturn_fake_exit_edges
PARAMS ((void));
279 extern void connect_infinite_loops_to_exit
PARAMS ((void));
280 extern int flow_call_edges_add
PARAMS ((sbitmap
));
281 extern rtx flow_delete_insn
PARAMS ((rtx
));
282 extern void flow_delete_insn_chain
PARAMS ((rtx
, rtx
));
283 extern void make_edge
PARAMS ((sbitmap
*, basic_block
,
285 extern void remove_edge
PARAMS ((edge
));
286 extern void redirect_edge_succ
PARAMS ((edge
, basic_block
));
287 extern void redirect_edge_pred
PARAMS ((edge
, basic_block
));
288 extern void create_basic_block
PARAMS ((int, rtx
, rtx
, rtx
));
289 extern int flow_delete_block
PARAMS ((basic_block
));
290 extern void merge_blocks_nomove
PARAMS ((basic_block
, basic_block
));
291 extern void tidy_fallthru_edge
PARAMS ((edge
, basic_block
,
293 extern int flow_depth_first_order_compute
PARAMS ((int *, int *));
294 extern void dump_edge_info
PARAMS ((FILE *, edge
, int));
295 extern void clear_edges
PARAMS ((void));
296 extern void mark_critical_edges
PARAMS ((void));
299 /* Structure to hold information for each natural loop. */
302 /* Index into loops array. */
305 /* Basic block of loop header. */
308 /* Basic block of loop latch. */
311 /* Basic block of loop pre-header or NULL if it does not exist. */
312 basic_block pre_header
;
314 /* Array of edges along the pre-header extended basic block trace.
315 The source of the first edge is the root node of pre-header
316 extended basic block, if it exists. */
317 edge
*pre_header_edges
;
319 /* Number of edges along the pre_header extended basic block trace. */
320 int num_pre_header_edges
;
322 /* The first block in the loop. This is not necessarily the same as
326 /* The last block in the loop. This is not necessarily the same as
330 /* Bitmap of blocks contained within the loop. */
333 /* Number of blocks contained within the loop. */
336 /* Array of edges that enter the loop. */
339 /* Number of edges that enter the loop. */
342 /* Array of edges that exit the loop. */
345 /* Number of edges that exit the loop. */
348 /* Bitmap of blocks that dominate all exits of the loop. */
351 /* The loop nesting depth. */
354 /* The height of the loop (enclosed loop levels) within the loop
358 /* The outer (parent) loop or NULL if outermost loop. */
361 /* The first inner (child) loop or NULL if innermost loop. */
364 /* Link to the next (sibling) loop. */
367 /* Non-zero if the loop shares a header with another loop. */
370 /* Non-zero if the loop is invalid (e.g., contains setjmp.). */
373 /* Auxiliary info specific to a pass. */
376 /* The following are currently used by loop.c but they are likely to
377 disappear as loop.c is converted to use the CFG. */
379 /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP. */
382 /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
383 A continue statement will generate a branch to NEXT_INSN (cont). */
386 /* The dominator of cont. */
389 /* The NOTE_INSN_LOOP_BEG. */
392 /* The NOTE_INSN_LOOP_END. */
395 /* For a rotated loop that is entered near the bottom,
396 this is the label at the top. Otherwise it is zero. */
399 /* Place in the loop where control enters. */
402 /* The position where to sink insns out of the loop. */
405 /* List of all LABEL_REFs which refer to code labels outside the
406 loop. Used by routines that need to know all loop exits, such as
407 final_biv_value and final_giv_value.
409 This does not include loop exits due to return instructions.
410 This is because all bivs and givs are pseudos, and hence must be
411 dead after a return, so the presense of a return does not affect
412 any of the optimizations that use this info. It is simpler to
413 just not include return instructions on this list. */
416 /* The number of LABEL_REFs on exit_labels for this loop and all
417 loops nested inside it. */
422 /* Structure to hold CFG information about natural loops within a function. */
425 /* Number of natural loops in the function. */
428 /* Maxium nested loop level in the function. */
431 /* Array of natural loop descriptors (scanning this array in reverse order
432 will find the inner loops before their enclosing outer loops). */
435 /* Pointer to root of loop heirachy tree. */
438 /* Information derived from the CFG. */
441 /* The bitmap vector of dominators or NULL if not computed. */
444 /* The ordering of the basic blocks in a depth first search. */
447 /* The reverse completion ordering of the basic blocks found in a
448 depth first search. */
452 /* Headers shared by multiple loops that should be merged. */
453 sbitmap shared_headers
;
456 extern int flow_loops_find
PARAMS ((struct loops
*, int flags
));
457 extern int flow_loops_update
PARAMS ((struct loops
*, int flags
));
458 extern void flow_loops_free
PARAMS ((struct loops
*));
459 extern void flow_loops_dump
PARAMS ((const struct loops
*, FILE *,
460 void (*)(const struct loop
*,
462 extern void flow_loop_dump
PARAMS ((const struct loop
*, FILE *,
463 void (*)(const struct loop
*,
465 extern int flow_loop_scan
PARAMS ((struct loops
*, struct loop
*, int));
467 /* This structure maintains an edge list vector. */
475 /* This is the value which indicates no edge is present. */
476 #define EDGE_INDEX_NO_EDGE -1
478 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
479 if there is no edge between the 2 basic blocks. */
480 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
482 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
483 block which is either the pred or succ end of the indexed edge. */
484 #define INDEX_EDGE_PRED_BB(el, index) ((el)->index_to_edge[(index)]->src)
485 #define INDEX_EDGE_SUCC_BB(el, index) ((el)->index_to_edge[(index)]->dest)
487 /* INDEX_EDGE returns a pointer to the edge. */
488 #define INDEX_EDGE(el, index) ((el)->index_to_edge[(index)])
490 /* Number of edges in the compressed edge list. */
491 #define NUM_EDGES(el) ((el)->num_edges)
493 /* BB is assumed to contain conditional jump. Return the fallthru edge. */
494 #define FALLTHRU_EDGE(bb) ((bb)->succ->flags & EDGE_FALLTHRU \
495 ? (bb)->succ : (bb)->succ->succ_next)
497 /* BB is assumed to contain conditional jump. Return the branch edge. */
498 #define BRANCH_EDGE(bb) ((bb)->succ->flags & EDGE_FALLTHRU \
499 ? (bb)->succ->succ_next : (bb)->succ)
501 struct edge_list
* create_edge_list
PARAMS ((void));
502 void free_edge_list
PARAMS ((struct edge_list
*));
503 void print_edge_list
PARAMS ((FILE *, struct edge_list
*));
504 void verify_edge_list
PARAMS ((FILE *, struct edge_list
*));
505 int find_edge_index
PARAMS ((struct edge_list
*,
506 basic_block
, basic_block
));
509 enum update_life_extent
511 UPDATE_LIFE_LOCAL
= 0,
512 UPDATE_LIFE_GLOBAL
= 1,
513 UPDATE_LIFE_GLOBAL_RM_NOTES
= 2
516 /* Flags for life_analysis and update_life_info. */
518 #define PROP_DEATH_NOTES 1 /* Create DEAD and UNUSED notes. */
519 #define PROP_LOG_LINKS 2 /* Create LOG_LINKS. */
520 #define PROP_REG_INFO 4 /* Update regs_ever_live et al. */
521 #define PROP_KILL_DEAD_CODE 8 /* Remove dead code. */
522 #define PROP_SCAN_DEAD_CODE 16 /* Scan for dead code. */
523 #define PROP_AUTOINC 32 /* Create autoinc mem references. */
524 #define PROP_FINAL 63 /* All of the above. */
526 /* Flags for loop discovery. */
528 #define LOOP_TREE 1 /* Build loop hierarchy tree. */
529 #define LOOP_PRE_HEADER 2 /* Analyse loop pre-header. */
530 #define LOOP_ENTRY_EDGES 4 /* Find entry edges. */
531 #define LOOP_EXIT_EDGES 8 /* Find exit edges. */
532 #define LOOP_EDGES (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
533 #define LOOP_EXITS_DOMS 16 /* Find nodes that dom. all exits. */
534 #define LOOP_ALL 31 /* All of the above */
536 extern void life_analysis
PARAMS ((rtx
, FILE *, int));
537 extern void update_life_info
PARAMS ((sbitmap
, enum update_life_extent
,
539 extern int count_or_remove_death_notes
PARAMS ((sbitmap
, int));
540 extern void propagate_block
PARAMS ((basic_block
, regset
, regset
, regset
,
543 struct propagate_block_info
;
544 extern rtx propagate_one_insn
PARAMS ((struct propagate_block_info
*, rtx
));
545 extern struct propagate_block_info
*init_propagate_block_info
546 PARAMS ((basic_block
, regset
, regset
, regset
, int));
547 extern void free_propagate_block_info
PARAMS ((struct propagate_block_info
*));
550 extern struct edge_list
*pre_edge_lcm
PARAMS ((FILE *, int, sbitmap
*,
551 sbitmap
*, sbitmap
*,
552 sbitmap
*, sbitmap
**,
554 extern struct edge_list
*pre_edge_rev_lcm
PARAMS ((FILE *, int, sbitmap
*,
555 sbitmap
*, sbitmap
*,
556 sbitmap
*, sbitmap
**,
558 extern void compute_available
PARAMS ((sbitmap
*, sbitmap
*,
559 sbitmap
*, sbitmap
*));
560 extern int optimize_mode_switching
PARAMS ((FILE *));
563 extern rtx emit_block_insn_after
PARAMS ((rtx
, rtx
, basic_block
));
564 extern rtx emit_block_insn_before
PARAMS ((rtx
, rtx
, basic_block
));
567 extern void estimate_probability
PARAMS ((struct loops
*));
568 extern void expected_value_to_br_prob
PARAMS ((void));
571 extern void init_flow
PARAMS ((void));
572 extern void reorder_basic_blocks
PARAMS ((void));
573 extern void dump_bb
PARAMS ((basic_block
, FILE *));
574 extern void debug_bb
PARAMS ((basic_block
));
575 extern void debug_bb_n
PARAMS ((int));
576 extern void dump_regset
PARAMS ((regset
, FILE *));
577 extern void debug_regset
PARAMS ((regset
));
578 extern void allocate_reg_life_data
PARAMS ((void));
579 extern void find_unreachable_blocks
PARAMS ((void));
581 /* This function is always defined so it can be called from the
582 debugger, and it is declared extern so we don't get warnings about
584 extern void verify_flow_info
PARAMS ((void));
585 extern int flow_loop_outside_edge_p
PARAMS ((const struct loop
*, edge
));
587 typedef struct conflict_graph_def
*conflict_graph
;
589 /* Callback function when enumerating conflicts. The arguments are
590 the smaller and larger regno in the conflict. Returns zero if
591 enumeration is to continue, non-zero to halt enumeration. */
592 typedef int (*conflict_graph_enum_fn
) PARAMS ((int, int, void *));
595 /* Prototypes of operations on conflict graphs. */
597 extern conflict_graph conflict_graph_new
599 extern void conflict_graph_delete
PARAMS ((conflict_graph
));
600 extern int conflict_graph_add
PARAMS ((conflict_graph
,
602 extern int conflict_graph_conflict_p
PARAMS ((conflict_graph
,
604 extern void conflict_graph_enum
PARAMS ((conflict_graph
, int,
605 conflict_graph_enum_fn
,
607 extern void conflict_graph_merge_regs
PARAMS ((conflict_graph
, int,
609 extern void conflict_graph_print
PARAMS ((conflict_graph
, FILE*));
610 extern conflict_graph conflict_graph_compute
622 extern void calculate_dominance_info
PARAMS ((int *, sbitmap
*,
623 enum cdi_direction
));
625 #endif /* GCC_BASIC_BLOCK_H */