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"
31 #define tree union tree_node *
34 /* Head of register set linked list. */
35 typedef bitmap_head regset_head
;
36 /* A pointer to a regset_head. */
37 typedef bitmap regset
;
39 /* Initialize a new regset. */
40 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD)
42 /* Clear a register set by freeing up the linked list. */
43 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
45 /* Copy a register set to another register set. */
46 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
48 /* Compare two register sets. */
49 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
51 /* `and' a register set with a second register set. */
52 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
54 /* `and' the complement of a register set with a register set. */
55 #define AND_COMPL_REG_SET(TO, FROM) \
56 bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
58 /* Inclusive or a register set with a second register set. */
59 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
61 /* Exclusive or a register set with a second register set. */
62 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
64 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2. */
65 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
66 bitmap_ior_and_compl (TO, FROM1, FROM2)
68 /* Clear a single register in a register set. */
69 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
71 /* Set a single register in a register set. */
72 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
74 /* Return true if a register is set in a register set. */
75 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
77 /* Copy the hard registers in a register set to the hard register set. */
78 extern void reg_set_to_hard_reg_set
PARAMS ((HARD_REG_SET
*, bitmap
));
79 #define REG_SET_TO_HARD_REG_SET(TO, FROM) \
81 CLEAR_HARD_REG_SET (TO); \
82 reg_set_to_hard_reg_set (&TO, FROM); \
85 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
86 register number and executing CODE for all registers that are set. */
87 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE) \
88 EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
90 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
91 REGNUM to the register number and executing CODE for all registers that are
92 set in the first regset and not set in the second. */
93 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
94 EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
96 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
97 REGNUM to the register number and executing CODE for all registers that are
98 set in both regsets. */
99 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
100 EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
102 /* Allocate a register set with oballoc. */
103 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
105 /* Initialize a register set. Returns the new register set. */
106 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD)
108 /* Do any cleanup needed on a regset when it is no longer used. */
109 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
111 /* Do any one-time initializations needed for regsets. */
112 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
114 /* Grow any tables needed when the number of registers is calculated
115 or extended. For the linked list allocation, nothing needs to
116 be done, other than zero the statistics on the first allocation. */
117 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
119 /* Type we use to hold basic block counters. Should be at least 64bit. */
120 typedef HOST_WIDEST_INT gcov_type
;
122 /* Control flow edge information. */
123 typedef struct edge_def
{
124 /* Links through the predecessor and successor lists. */
125 struct edge_def
*pred_next
, *succ_next
;
127 /* The two blocks at the ends of the edge. */
128 struct basic_block_def
*src
, *dest
;
130 /* Instructions queued on the edge. */
133 /* Auxiliary info specific to a pass. */
136 int flags
; /* see EDGE_* below */
137 int probability
; /* biased by REG_BR_PROB_BASE */
138 gcov_type count
; /* Expected number of executions calculated
142 #define EDGE_FALLTHRU 1
143 #define EDGE_CRITICAL 2
144 #define EDGE_ABNORMAL 4
145 #define EDGE_ABNORMAL_CALL 8
149 #define EDGE_COMPLEX (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
152 /* A basic block is a sequence of instructions with only entry and
153 only one exit. If any one of the instructions are executed, they
154 will all be executed, and in sequence from first to last.
156 There may be COND_EXEC instructions in the basic block. The
157 COND_EXEC *instructions* will be executed -- but if the condition
158 is false the conditionally executed *expressions* will of course
159 not be executed. We don't consider the conditionally executed
160 expression (which might have side-effects) to be in a separate
161 basic block because the program counter will always be at the same
162 location after the COND_EXEC instruction, regardless of whether the
163 condition is true or not.
165 Basic blocks need not start with a label nor end with a jump insn.
166 For example, a previous basic block may just "conditionally fall"
167 into the succeeding basic block, and the last basic block need not
168 end with a jump insn. Block 0 is a descendant of the entry block.
170 A basic block beginning with two labels cannot have notes between
173 Data for jump tables are stored in jump_insns that occur in no
174 basic block even though these insns can follow or precede insns in
177 /* Basic block information indexed by block number. */
178 typedef struct basic_block_def
{
179 /* The first and last insns of the block. */
182 /* The first and last trees of the block. */
186 /* The edges into and out of the block. */
191 /* The registers that are modified within this in block. */
193 /* The registers that are conditionally modified within this block.
194 In other words, registers that are set only as part of a
196 regset cond_local_set
;
197 /* The registers that are live on entry to this block.
199 Note that in SSA form, global_live_at_start does not reflect the
200 use of regs in phi functions, since the liveness of these regs
201 may depend on which edge was taken into the block. */
202 regset global_live_at_start
;
203 /* The registers that are live on exit from this block. */
204 regset global_live_at_end
;
206 /* Auxiliary info specific to a pass. */
209 /* The index of this block. */
212 /* The loop depth of this block. */
215 /* Expected number of executions: calculated in profile.c. */
218 /* Expected frequency. Normalized to be in range 0 to BB_FREQ_MAX. */
222 #define BB_FREQ_MAX 10000
224 /* Number of basic blocks in the current function. */
226 extern int n_basic_blocks
;
228 /* Number of edges in the current function. */
232 /* Index by basic block number, get basic block struct info. */
234 extern varray_type basic_block_info
;
236 #define BASIC_BLOCK(N) (VARRAY_BB (basic_block_info, (N)))
238 /* What registers are live at the setjmp call. */
240 extern regset regs_live_at_setjmp
;
242 /* Indexed by n, gives number of basic block that (REG n) is used in.
243 If the value is REG_BLOCK_GLOBAL (-2),
244 it means (REG n) is used in more than one basic block.
245 REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
246 This information remains valid for the rest of the compilation
247 of the current function; it is used to control register allocation. */
249 #define REG_BLOCK_UNKNOWN -1
250 #define REG_BLOCK_GLOBAL -2
252 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
254 /* Stuff for recording basic block info. */
256 #define BLOCK_HEAD(B) (BASIC_BLOCK (B)->head)
257 #define BLOCK_END(B) (BASIC_BLOCK (B)->end)
259 #define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
260 #define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
262 /* Special block numbers [markers] for entry and exit. */
263 #define ENTRY_BLOCK (-1)
264 #define EXIT_BLOCK (-2)
266 /* Special block number not valid for any block. */
267 #define INVALID_BLOCK (-3)
269 /* Similarly, block pointers for the edge list. */
270 extern struct basic_block_def entry_exit_blocks
[2];
271 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
272 #define EXIT_BLOCK_PTR (&entry_exit_blocks[1])
274 extern varray_type basic_block_for_insn
;
275 #define BLOCK_FOR_INSN(INSN) VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
276 #define BLOCK_NUM(INSN) (BLOCK_FOR_INSN (INSN)->index + 0)
278 extern void compute_bb_for_insn
PARAMS ((int));
279 extern void update_bb_for_insn
PARAMS ((basic_block
));
280 extern void set_block_for_insn
PARAMS ((rtx
, basic_block
));
281 extern void set_block_for_new_insns
PARAMS ((rtx
, basic_block
));
283 extern void free_basic_block_vars
PARAMS ((int));
285 extern edge split_block
PARAMS ((basic_block
, rtx
));
286 extern basic_block split_edge
PARAMS ((edge
));
287 extern void insert_insn_on_edge
PARAMS ((rtx
, edge
));
288 extern void commit_edge_insertions
PARAMS ((void));
289 extern void remove_fake_edges
PARAMS ((void));
290 extern void add_noreturn_fake_exit_edges
PARAMS ((void));
291 extern void connect_infinite_loops_to_exit
PARAMS ((void));
292 extern int flow_call_edges_add
PARAMS ((sbitmap
));
293 extern rtx flow_delete_insn
PARAMS ((rtx
));
294 extern void flow_delete_insn_chain
PARAMS ((rtx
, rtx
));
295 extern void make_edge
PARAMS ((sbitmap
*, basic_block
,
297 extern void remove_edge
PARAMS ((edge
));
298 extern void redirect_edge_succ
PARAMS ((edge
, basic_block
));
299 extern void redirect_edge_pred
PARAMS ((edge
, basic_block
));
300 extern void create_basic_block
PARAMS ((int, rtx
, rtx
, rtx
));
301 extern int flow_delete_block
PARAMS ((basic_block
));
302 extern void merge_blocks_nomove
PARAMS ((basic_block
, basic_block
));
303 extern void tidy_fallthru_edge
PARAMS ((edge
, basic_block
,
305 extern int flow_depth_first_order_compute
PARAMS ((int *, int *));
306 extern void dump_edge_info
PARAMS ((FILE *, edge
, int));
307 extern void clear_edges
PARAMS ((void));
308 extern void mark_critical_edges
PARAMS ((void));
309 extern rtx first_insn_after_basic_block_note
PARAMS ((basic_block
));
311 /* Structure to hold information for each natural loop. */
314 /* Index into loops array. */
317 /* Basic block of loop header. */
320 /* Basic block of loop latch. */
323 /* Basic block of loop pre-header or NULL if it does not exist. */
324 basic_block pre_header
;
326 /* Array of edges along the pre-header extended basic block trace.
327 The source of the first edge is the root node of pre-header
328 extended basic block, if it exists. */
329 edge
*pre_header_edges
;
331 /* Number of edges along the pre_header extended basic block trace. */
332 int num_pre_header_edges
;
334 /* The first block in the loop. This is not necessarily the same as
338 /* The last block in the loop. This is not necessarily the same as
342 /* Bitmap of blocks contained within the loop. */
345 /* Number of blocks contained within the loop. */
348 /* Array of edges that enter the loop. */
351 /* Number of edges that enter the loop. */
354 /* Array of edges that exit the loop. */
357 /* Number of edges that exit the loop. */
360 /* Bitmap of blocks that dominate all exits of the loop. */
363 /* The loop nesting depth. */
366 /* The height of the loop (enclosed loop levels) within the loop
370 /* The outer (parent) loop or NULL if outermost loop. */
373 /* The first inner (child) loop or NULL if innermost loop. */
376 /* Link to the next (sibling) loop. */
379 /* Non-zero if the loop shares a header with another loop. */
382 /* Non-zero if the loop is invalid (e.g., contains setjmp.). */
385 /* Auxiliary info specific to a pass. */
388 /* The following are currently used by loop.c but they are likely to
389 disappear as loop.c is converted to use the CFG. */
391 /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP. */
394 /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
395 A continue statement will generate a branch to NEXT_INSN (cont). */
398 /* The dominator of cont. */
401 /* The NOTE_INSN_LOOP_BEG. */
404 /* The NOTE_INSN_LOOP_END. */
407 /* For a rotated loop that is entered near the bottom,
408 this is the label at the top. Otherwise it is zero. */
411 /* Place in the loop where control enters. */
414 /* The position where to sink insns out of the loop. */
417 /* List of all LABEL_REFs which refer to code labels outside the
418 loop. Used by routines that need to know all loop exits, such as
419 final_biv_value and final_giv_value.
421 This does not include loop exits due to return instructions.
422 This is because all bivs and givs are pseudos, and hence must be
423 dead after a return, so the presense of a return does not affect
424 any of the optimizations that use this info. It is simpler to
425 just not include return instructions on this list. */
428 /* The number of LABEL_REFs on exit_labels for this loop and all
429 loops nested inside it. */
434 /* Structure to hold CFG information about natural loops within a function. */
437 /* Number of natural loops in the function. */
440 /* Maxium nested loop level in the function. */
443 /* Array of natural loop descriptors (scanning this array in reverse order
444 will find the inner loops before their enclosing outer loops). */
447 /* Pointer to root of loop heirachy tree. */
448 struct loop
*tree_root
;
450 /* Information derived from the CFG. */
453 /* The bitmap vector of dominators or NULL if not computed. */
456 /* The ordering of the basic blocks in a depth first search. */
459 /* The reverse completion ordering of the basic blocks found in a
460 depth first search. */
464 /* Headers shared by multiple loops that should be merged. */
465 sbitmap shared_headers
;
468 extern int flow_loops_find
PARAMS ((struct loops
*, int flags
));
469 extern int flow_loops_update
PARAMS ((struct loops
*, int flags
));
470 extern void flow_loops_free
PARAMS ((struct loops
*));
471 extern void flow_loops_dump
PARAMS ((const struct loops
*, FILE *,
472 void (*)(const struct loop
*,
474 extern void flow_loop_dump
PARAMS ((const struct loop
*, FILE *,
475 void (*)(const struct loop
*,
477 extern int flow_loop_scan
PARAMS ((struct loops
*, struct loop
*, int));
479 /* This structure maintains an edge list vector. */
487 /* This is the value which indicates no edge is present. */
488 #define EDGE_INDEX_NO_EDGE -1
490 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
491 if there is no edge between the 2 basic blocks. */
492 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
494 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
495 block which is either the pred or succ end of the indexed edge. */
496 #define INDEX_EDGE_PRED_BB(el, index) ((el)->index_to_edge[(index)]->src)
497 #define INDEX_EDGE_SUCC_BB(el, index) ((el)->index_to_edge[(index)]->dest)
499 /* INDEX_EDGE returns a pointer to the edge. */
500 #define INDEX_EDGE(el, index) ((el)->index_to_edge[(index)])
502 /* Number of edges in the compressed edge list. */
503 #define NUM_EDGES(el) ((el)->num_edges)
505 /* BB is assumed to contain conditional jump. Return the fallthru edge. */
506 #define FALLTHRU_EDGE(bb) ((bb)->succ->flags & EDGE_FALLTHRU \
507 ? (bb)->succ : (bb)->succ->succ_next)
509 /* BB is assumed to contain conditional jump. Return the branch edge. */
510 #define BRANCH_EDGE(bb) ((bb)->succ->flags & EDGE_FALLTHRU \
511 ? (bb)->succ->succ_next : (bb)->succ)
513 struct edge_list
* create_edge_list
PARAMS ((void));
514 void free_edge_list
PARAMS ((struct edge_list
*));
515 void print_edge_list
PARAMS ((FILE *, struct edge_list
*));
516 void verify_edge_list
PARAMS ((FILE *, struct edge_list
*));
517 int find_edge_index
PARAMS ((struct edge_list
*,
518 basic_block
, basic_block
));
521 enum update_life_extent
523 UPDATE_LIFE_LOCAL
= 0,
524 UPDATE_LIFE_GLOBAL
= 1,
525 UPDATE_LIFE_GLOBAL_RM_NOTES
= 2
528 /* Flags for life_analysis and update_life_info. */
530 #define PROP_DEATH_NOTES 1 /* Create DEAD and UNUSED notes. */
531 #define PROP_LOG_LINKS 2 /* Create LOG_LINKS. */
532 #define PROP_REG_INFO 4 /* Update regs_ever_live et al. */
533 #define PROP_KILL_DEAD_CODE 8 /* Remove dead code. */
534 #define PROP_SCAN_DEAD_CODE 16 /* Scan for dead code. */
535 #define PROP_AUTOINC 32 /* Create autoinc mem references. */
536 #define PROP_FINAL 63 /* All of the above. */
538 #define CLEANUP_EXPENSIVE 1 /* Do relativly expensive optimizations
539 except for edge forwarding */
540 #define CLEANUP_CROSSJUMP 2 /* Do crossjumping. */
541 #define CLEANUP_POST_REGSTACK 4 /* We run after reg-stack and need
542 to care REG_DEAD notes. */
543 /* Flags for loop discovery. */
545 #define LOOP_TREE 1 /* Build loop hierarchy tree. */
546 #define LOOP_PRE_HEADER 2 /* Analyse loop pre-header. */
547 #define LOOP_ENTRY_EDGES 4 /* Find entry edges. */
548 #define LOOP_EXIT_EDGES 8 /* Find exit edges. */
549 #define LOOP_EDGES (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
550 #define LOOP_EXITS_DOMS 16 /* Find nodes that dom. all exits. */
551 #define LOOP_ALL 31 /* All of the above */
553 extern void life_analysis
PARAMS ((rtx
, FILE *, int));
554 extern void update_life_info
PARAMS ((sbitmap
, enum update_life_extent
,
556 extern int count_or_remove_death_notes
PARAMS ((sbitmap
, int));
557 extern void propagate_block
PARAMS ((basic_block
, regset
, regset
, regset
,
560 struct propagate_block_info
;
561 extern rtx propagate_one_insn
PARAMS ((struct propagate_block_info
*, rtx
));
562 extern struct propagate_block_info
*init_propagate_block_info
563 PARAMS ((basic_block
, regset
, regset
, regset
, int));
564 extern void free_propagate_block_info
PARAMS ((struct propagate_block_info
*));
567 extern struct edge_list
*pre_edge_lcm
PARAMS ((FILE *, int, sbitmap
*,
568 sbitmap
*, sbitmap
*,
569 sbitmap
*, sbitmap
**,
571 extern struct edge_list
*pre_edge_rev_lcm
PARAMS ((FILE *, int, sbitmap
*,
572 sbitmap
*, sbitmap
*,
573 sbitmap
*, sbitmap
**,
575 extern void compute_available
PARAMS ((sbitmap
*, sbitmap
*,
576 sbitmap
*, sbitmap
*));
577 extern int optimize_mode_switching
PARAMS ((FILE *));
580 extern rtx emit_block_insn_after
PARAMS ((rtx
, rtx
, basic_block
));
581 extern rtx emit_block_insn_before
PARAMS ((rtx
, rtx
, basic_block
));
584 extern void estimate_probability
PARAMS ((struct loops
*));
585 extern void expected_value_to_br_prob
PARAMS ((void));
588 extern void init_flow
PARAMS ((void));
589 extern void reorder_basic_blocks
PARAMS ((void));
590 extern void dump_bb
PARAMS ((basic_block
, FILE *));
591 extern void debug_bb
PARAMS ((basic_block
));
592 extern void debug_bb_n
PARAMS ((int));
593 extern void dump_regset
PARAMS ((regset
, FILE *));
594 extern void debug_regset
PARAMS ((regset
));
595 extern void allocate_reg_life_data
PARAMS ((void));
596 extern void find_unreachable_blocks
PARAMS ((void));
598 /* This function is always defined so it can be called from the
599 debugger, and it is declared extern so we don't get warnings about
601 extern void verify_flow_info
PARAMS ((void));
602 extern int flow_loop_outside_edge_p
PARAMS ((const struct loop
*, edge
));
604 typedef struct conflict_graph_def
*conflict_graph
;
606 /* Callback function when enumerating conflicts. The arguments are
607 the smaller and larger regno in the conflict. Returns zero if
608 enumeration is to continue, non-zero to halt enumeration. */
609 typedef int (*conflict_graph_enum_fn
) PARAMS ((int, int, void *));
612 /* Prototypes of operations on conflict graphs. */
614 extern conflict_graph conflict_graph_new
616 extern void conflict_graph_delete
PARAMS ((conflict_graph
));
617 extern int conflict_graph_add
PARAMS ((conflict_graph
,
619 extern int conflict_graph_conflict_p
PARAMS ((conflict_graph
,
621 extern void conflict_graph_enum
PARAMS ((conflict_graph
, int,
622 conflict_graph_enum_fn
,
624 extern void conflict_graph_merge_regs
PARAMS ((conflict_graph
, int,
626 extern void conflict_graph_print
PARAMS ((conflict_graph
, FILE*));
627 extern conflict_graph conflict_graph_compute
639 extern void calculate_dominance_info
PARAMS ((int *, sbitmap
*,
640 enum cdi_direction
));
642 #endif /* GCC_BASIC_BLOCK_H */