2003-03-13 Aldy Hernandez <aldyh@redhat.com>

[official-gcc.git] / gcc / basic-block.h

/* Define control and data flow tables, and regsets.
   Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003
   Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

#ifndef GCC_BASIC_BLOCK_H
#define GCC_BASIC_BLOCK_H

#include "bitmap.h"
#include "sbitmap.h"
#include "varray.h"
#include "partition.h"
#include "hard-reg-set.h"

/* Head of register set linked list.  */
typedef bitmap_head regset_head;
/* A pointer to a regset_head.  */
typedef bitmap regset;

/* Initialize a new regset.  */
#define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, 1)

/* Clear a register set by freeing up the linked list.  */
#define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)

/* Copy a register set to another register set.  */
#define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)

/* Compare two register sets.  */
#define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)

/* `and' a register set with a second register set.  */
#define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)

/* `and' the complement of a register set with a register set.  */
#define AND_COMPL_REG_SET(TO, FROM) \
  bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)

/* Inclusive or a register set with a second register set.  */
#define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)

/* Exclusive or a register set with a second register set.  */
#define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)

/* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
#define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  bitmap_ior_and_compl (TO, FROM1, FROM2)

/* Clear a single register in a register set.  */
#define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)

/* Set a single register in a register set.  */
#define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)

/* Return true if a register is set in a register set.  */
#define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)

/* Copy the hard registers in a register set to the hard register set.  */
extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
#define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
do {                                                                    \
  CLEAR_HARD_REG_SET (TO);                                              \
  reg_set_to_hard_reg_set (&TO, FROM);                                  \
} while (0)

/* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
   register number and executing CODE for all registers that are set.  */
#define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)

/* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
   REGNUM to the register number and executing CODE for all registers that are
   set in the first regset and not set in the second.  */
#define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)

/* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
   REGNUM to the register number and executing CODE for all registers that are
   set in both regsets.  */
#define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)

/* Allocate a register set with oballoc.  */
#define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)

/* Initialize a register set.  Returns the new register set.  */
#define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD, 1)

/* Do any cleanup needed on a regset when it is no longer used.  */
#define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)

/* Do any one-time initializations needed for regsets.  */
#define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()

/* Grow any tables needed when the number of registers is calculated
   or extended.  For the linked list allocation, nothing needs to
   be done, other than zero the statistics on the first allocation.  */
#define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)

/* Type we use to hold basic block counters.  Should be at least
   64bit.  Although a counter cannot be negative, we use a signed
   type, because erroneous negative counts can be generated when the
   flow graph is manipulated by various optimizations.  A signed type
   makes those easy to detect.  */
typedef HOST_WIDEST_INT gcov_type;

/* Control flow edge information.  */
typedef struct edge_def {
  /* Links through the predecessor and successor lists.  */
  struct edge_def *pred_next, *succ_next;

  /* The two blocks at the ends of the edge.  */
  struct basic_block_def *src, *dest;

  /* Instructions queued on the edge.  */
  rtx insns;

  /* Auxiliary info specific to a pass.  */
  void *aux;

  int flags;                    /* see EDGE_* below  */
  int probability;              /* biased by REG_BR_PROB_BASE */
  gcov_type count;              /* Expected number of executions calculated
                                   in profile.c  */
} *edge;

#define EDGE_FALLTHRU           1       /* 'Straight line' flow */
#define EDGE_ABNORMAL           2       /* Strange flow, like computed
                                           label, or eh */
#define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
                                           like an exception, or sibcall */
#define EDGE_EH                 8       /* Exception throw */
#define EDGE_FAKE               16      /* Not a real edge (profile.c) */
#define EDGE_DFS_BACK           32      /* A backwards edge */
#define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
                                           flow.  */
#define EDGE_IRREDUCIBLE_LOOP   128     /* Part of irreducible loop.  */
#define EDGE_ALL_FLAGS          255

#define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)

/* Declared in cfgloop.h.  */
struct loop;
struct loops;

/* A basic block is a sequence of instructions with only entry and
   only one exit.  If any one of the instructions are executed, they
   will all be executed, and in sequence from first to last.

   There may be COND_EXEC instructions in the basic block.  The
   COND_EXEC *instructions* will be executed -- but if the condition
   is false the conditionally executed *expressions* will of course
   not be executed.  We don't consider the conditionally executed
   expression (which might have side-effects) to be in a separate
   basic block because the program counter will always be at the same
   location after the COND_EXEC instruction, regardless of whether the
   condition is true or not.

   Basic blocks need not start with a label nor end with a jump insn.
   For example, a previous basic block may just "conditionally fall"
   into the succeeding basic block, and the last basic block need not
   end with a jump insn.  Block 0 is a descendant of the entry block.

   A basic block beginning with two labels cannot have notes between
   the labels.

   Data for jump tables are stored in jump_insns that occur in no
   basic block even though these insns can follow or precede insns in
   basic blocks.  */

/* Basic block information indexed by block number.  */
typedef struct basic_block_def {
  /* The first and last insns of the block.  */
  rtx head, end;

  /* The first and last trees of the block.  */
  tree head_tree;
  tree end_tree;

  /* The edges into and out of the block.  */
  edge pred, succ;

  /* Liveness info.  */

  /* The registers that are modified within this in block.  */
  regset local_set;
  /* The registers that are conditionally modified within this block.
     In other words, registers that are set only as part of a
     COND_EXEC.  */
  regset cond_local_set;
  /* The registers that are live on entry to this block.

     Note that in SSA form, global_live_at_start does not reflect the
     use of regs in phi functions, since the liveness of these regs
     may depend on which edge was taken into the block.  */
  regset global_live_at_start;
  /* The registers that are live on exit from this block.  */
  regset global_live_at_end;

  /* Auxiliary info specific to a pass.  */
  void *aux;

  /* The index of this block.  */
  int index;

  /* Previous and next blocks in the chain.  */
  struct basic_block_def *prev_bb, *next_bb;

  /* The loop depth of this block.  */
  int loop_depth;

  /* Outermost loop containing the block.  */
  struct loop *loop_father;

  /* Expected number of executions: calculated in profile.c.  */
  gcov_type count;

  /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
  int frequency;

  /* Various flags.  See BB_* below.  */
  int flags;
} *basic_block;

#define BB_FREQ_MAX 10000

/* Masks for basic_block.flags.  */
#define BB_DIRTY                1
#define BB_NEW                  2
#define BB_REACHABLE            4
#define BB_VISITED              8
#define BB_IRREDUCIBLE_LOOP     16
#define BB_SUPERBLOCK           32

/* Number of basic blocks in the current function.  */

extern int n_basic_blocks;

/* First free basic block number.  */

extern int last_basic_block;

/* Number of edges in the current function.  */

extern int n_edges;

/* Index by basic block number, get basic block struct info.  */

extern varray_type basic_block_info;

#define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))

/* For iterating over basic blocks.  */
#define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
  for (BB = FROM; BB != TO; BB = BB->DIR)

#define FOR_EACH_BB(BB) \
  FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)

#define FOR_EACH_BB_REVERSE(BB) \
  FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)

/* Cycles through _all_ basic blocks, even the fake ones (entry and
   exit block).  */

#define FOR_ALL_BB(BB) \
  for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)

/* What registers are live at the setjmp call.  */

extern regset regs_live_at_setjmp;

/* Special labels found during CFG build.  */

extern GTY(()) rtx label_value_list;
extern GTY(()) rtx tail_recursion_label_list;

extern struct obstack flow_obstack;

/* Indexed by n, gives number of basic block that  (REG n) is used in.
   If the value is REG_BLOCK_GLOBAL (-2),
   it means (REG n) is used in more than one basic block.
   REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
   This information remains valid for the rest of the compilation
   of the current function; it is used to control register allocation.  */

#define REG_BLOCK_UNKNOWN -1
#define REG_BLOCK_GLOBAL -2

#define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
\f
/* Stuff for recording basic block info.  */

#define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
#define BLOCK_END(B)       (BASIC_BLOCK (B)->end)

#define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
#define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)

/* Special block numbers [markers] for entry and exit.  */
#define ENTRY_BLOCK (-1)
#define EXIT_BLOCK (-2)

/* Special block number not valid for any block.  */
#define INVALID_BLOCK (-3)

/* Similarly, block pointers for the edge list.  */
extern struct basic_block_def entry_exit_blocks[2];
#define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
#define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])

#define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
#define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)

extern void compute_bb_for_insn         PARAMS ((void));
extern void free_bb_for_insn            PARAMS ((void));
extern void update_bb_for_insn          PARAMS ((basic_block));

extern void free_basic_block_vars       PARAMS ((int));

extern edge split_block                 PARAMS ((basic_block, rtx));
extern basic_block split_edge           PARAMS ((edge));
extern void insert_insn_on_edge         PARAMS ((rtx, edge));

extern void commit_edge_insertions      PARAMS ((void));
extern void commit_edge_insertions_watch_calls  PARAMS ((void));

extern void remove_fake_edges           PARAMS ((void));
extern void add_noreturn_fake_exit_edges        PARAMS ((void));
extern void connect_infinite_loops_to_exit      PARAMS ((void));
extern int flow_call_edges_add          PARAMS ((sbitmap));
extern edge unchecked_make_edge         PARAMS ((basic_block,
                                                 basic_block, int));
extern edge cached_make_edge            PARAMS ((sbitmap *, basic_block,
                                                 basic_block, int));
extern edge make_edge                   PARAMS ((basic_block,
                                                 basic_block, int));
extern edge make_single_succ_edge       PARAMS ((basic_block,
                                                 basic_block, int));
extern void remove_edge                 PARAMS ((edge));
extern void redirect_edge_succ          PARAMS ((edge, basic_block));
extern edge redirect_edge_succ_nodup    PARAMS ((edge, basic_block));
extern void redirect_edge_pred          PARAMS ((edge, basic_block));
extern basic_block create_basic_block_structure PARAMS ((rtx, rtx, rtx, basic_block));
extern basic_block create_basic_block   PARAMS ((rtx, rtx, basic_block));
extern int flow_delete_block            PARAMS ((basic_block));
extern int flow_delete_block_noexpunge  PARAMS ((basic_block));
extern void clear_bb_flags              PARAMS ((void));
extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
                                                 basic_block));
extern void tidy_fallthru_edges         PARAMS ((void));
extern void flow_reverse_top_sort_order_compute PARAMS ((int *));
extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
extern void flow_preorder_transversal_compute   PARAMS ((int *));
extern int dfs_enumerate_from           PARAMS ((basic_block, int,
                                                bool (*)(basic_block, void *),
                                                basic_block *, int, void *));
extern void dump_edge_info              PARAMS ((FILE *, edge, int));
extern void clear_edges                 PARAMS ((void));
extern void mark_critical_edges         PARAMS ((void));
extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));

/* Dominator information for basic blocks.  */

typedef struct dominance_info *dominance_info;

/* Structure to group all of the information to process IF-THEN and
   IF-THEN-ELSE blocks for the conditional execution support.  This
   needs to be in a public file in case the IFCVT macros call
   functions passing the ce_if_block data structure.  */

typedef struct ce_if_block
{
  basic_block test_bb;                  /* First test block.  */
  basic_block then_bb;                  /* THEN block.  */
  basic_block else_bb;                  /* ELSE block or NULL.  */
  basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
  basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
  int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
  int num_and_and_blocks;               /* # of && blocks.  */
  int num_or_or_blocks;                 /* # of || blocks.  */
  int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
  int and_and_p;                        /* Complex test is &&.  */
  int num_then_insns;                   /* # of insns in THEN block.  */
  int num_else_insns;                   /* # of insns in ELSE block.  */
  int pass;                             /* Pass number.  */

#ifdef IFCVT_EXTRA_FIELDS
  IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
#endif

} ce_if_block_t;

/* This structure maintains an edge list vector.  */
struct edge_list
{
  int num_blocks;
  int num_edges;
  edge *index_to_edge;
};

/* This is the value which indicates no edge is present.  */
#define EDGE_INDEX_NO_EDGE      -1

/* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
   if there is no edge between the 2 basic blocks.  */
#define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))

/* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
   block which is either the pred or succ end of the indexed edge.  */
#define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
#define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)

/* INDEX_EDGE returns a pointer to the edge.  */
#define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])

/* Number of edges in the compressed edge list.  */
#define NUM_EDGES(el)                   ((el)->num_edges)

/* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
#define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
                                         ? (bb)->succ : (bb)->succ->succ_next)

/* BB is assumed to contain conditional jump.  Return the branch edge.  */
#define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
                                         ? (bb)->succ->succ_next : (bb)->succ)

/* Return expected execution frequency of the edge E.  */
#define EDGE_FREQUENCY(e)               (((e)->src->frequency \
                                          * (e)->probability \
                                          + REG_BR_PROB_BASE / 2) \
                                         / REG_BR_PROB_BASE)

/* Return nonzero if edge is critical.  */
#define EDGE_CRITICAL_P(e)              ((e)->src->succ->succ_next \
                                         && (e)->dest->pred->pred_next)

struct edge_list * create_edge_list     PARAMS ((void));
void free_edge_list                     PARAMS ((struct edge_list *));
void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
int find_edge_index                     PARAMS ((struct edge_list *,
                                                 basic_block, basic_block));


enum update_life_extent
{
  UPDATE_LIFE_LOCAL = 0,
  UPDATE_LIFE_GLOBAL = 1,
  UPDATE_LIFE_GLOBAL_RM_NOTES = 2
};

/* Flags for life_analysis and update_life_info.  */

#define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
#define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
#define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
#define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
#define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
#define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
                                           by dead code removal.  */
#define PROP_AUTOINC            64      /* Create autoinc mem references.  */
#define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
#define PROP_SCAN_DEAD_STORES   256     /* Scan for dead code.  */
#define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
                                 | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
                                 | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
                                 | PROP_ALLOW_CFG_CHANGES \
                                 | PROP_SCAN_DEAD_STORES)

#define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
                                           except for edge forwarding */
#define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
#define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
                                           to care REG_DEAD notes.  */
#define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
                                           inside call_placeholders..  */
#define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
                                           notes.  */
#define CLEANUP_UPDATE_LIFE     32      /* Keep life information up to date.  */
#define CLEANUP_THREADING       64      /* Do jump threading.  */
#define CLEANUP_NO_INSN_DEL     128     /* Do not try to delete trivially dead
                                           insns.  */
extern void life_analysis       PARAMS ((rtx, FILE *, int));
extern int update_life_info     PARAMS ((sbitmap, enum update_life_extent,
                                         int));
extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
                                                      int));
extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
                                         int));

struct propagate_block_info;
extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
extern struct propagate_block_info *init_propagate_block_info
  PARAMS ((basic_block, regset, regset, regset, int));
extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));

/* In lcm.c */
extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
                                                 sbitmap *, sbitmap *,
                                                 sbitmap *, sbitmap **,
                                                 sbitmap **));
extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
                                                   sbitmap *, sbitmap *,
                                                   sbitmap *, sbitmap **,
                                                   sbitmap **));
extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
                                                 sbitmap *, sbitmap *));
extern int optimize_mode_switching      PARAMS ((FILE *));

/* In emit-rtl.c.  */
extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));

/* In predict.c */
extern void estimate_probability        PARAMS ((struct loops *));
extern void note_prediction_to_br_prob  PARAMS ((void));
extern void expected_value_to_br_prob   PARAMS ((void));
extern void note_prediction_to_br_prob  PARAMS ((void));
extern bool maybe_hot_bb_p              PARAMS ((basic_block));
extern bool probably_cold_bb_p          PARAMS ((basic_block));
extern bool probably_never_executed_bb_p PARAMS ((basic_block));

/* In flow.c */
extern void init_flow                   PARAMS ((void));
extern void reorder_basic_blocks        PARAMS ((void));
extern void dump_bb                     PARAMS ((basic_block, FILE *));
extern void debug_bb                    PARAMS ((basic_block));
extern basic_block debug_bb_n           PARAMS ((int));
extern void dump_regset                 PARAMS ((regset, FILE *));
extern void debug_regset                PARAMS ((regset));
extern void allocate_reg_life_data      PARAMS ((void));
extern void allocate_bb_life_data       PARAMS ((void));
extern void expunge_block               PARAMS ((basic_block));
extern void link_block                  PARAMS ((basic_block, basic_block));
extern void unlink_block                PARAMS ((basic_block));
extern void compact_blocks              PARAMS ((void));
extern basic_block alloc_block          PARAMS ((void));
extern void find_unreachable_blocks     PARAMS ((void));
extern int delete_noop_moves            PARAMS ((rtx));
extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
extern basic_block force_nonfallthru    PARAMS ((edge));
extern bool redirect_edge_and_branch    PARAMS ((edge, basic_block));
extern rtx block_label                  PARAMS ((basic_block));
extern bool forwarder_block_p           PARAMS ((basic_block));
extern bool purge_all_dead_edges        PARAMS ((int));
extern bool purge_dead_edges            PARAMS ((basic_block));
extern void find_sub_basic_blocks       PARAMS ((basic_block));
extern void find_many_sub_basic_blocks  PARAMS ((sbitmap));
extern bool can_fallthru                PARAMS ((basic_block, basic_block));
extern void flow_nodes_print            PARAMS ((const char *, const sbitmap,
                                                 FILE *));
extern void flow_edge_list_print        PARAMS ((const char *, const edge *,
                                                 int, FILE *));
extern void alloc_aux_for_block         PARAMS ((basic_block, int));
extern void alloc_aux_for_blocks        PARAMS ((int));
extern void clear_aux_for_blocks        PARAMS ((void));
extern void free_aux_for_blocks         PARAMS ((void));
extern void alloc_aux_for_edge          PARAMS ((edge, int));
extern void alloc_aux_for_edges         PARAMS ((int));
extern void clear_aux_for_edges         PARAMS ((void));
extern void free_aux_for_edges          PARAMS ((void));

/* This function is always defined so it can be called from the
   debugger, and it is declared extern so we don't get warnings about
   it being unused.  */
extern void verify_flow_info            PARAMS ((void));

typedef struct conflict_graph_def *conflict_graph;

/* Callback function when enumerating conflicts.  The arguments are
   the smaller and larger regno in the conflict.  Returns zero if
   enumeration is to continue, nonzero to halt enumeration.  */
typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));


/* Prototypes of operations on conflict graphs.  */

extern conflict_graph conflict_graph_new
                                        PARAMS ((int));
extern void conflict_graph_delete       PARAMS ((conflict_graph));
extern int conflict_graph_add           PARAMS ((conflict_graph,
                                                 int, int));
extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
                                                 int, int));
extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
                                                 conflict_graph_enum_fn,
                                                 void *));
extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
                                                 int));
extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
extern conflict_graph conflict_graph_compute
                                        PARAMS ((regset,
                                                 partition));
extern bool mark_dfs_back_edges         PARAMS ((void));
extern void set_edge_can_fallthru_flag  PARAMS ((void));
extern void update_br_prob_note         PARAMS ((basic_block));
extern void fixup_abnormal_edges        PARAMS ((void));
extern bool can_hoist_insn_p            PARAMS ((rtx, rtx, regset));
extern rtx hoist_insn_after             PARAMS ((rtx, rtx, rtx, rtx));
extern rtx hoist_insn_to_edge           PARAMS ((rtx, edge, rtx, rtx));
extern bool inside_basic_block_p        PARAMS ((rtx));
extern bool control_flow_insn_p         PARAMS ((rtx));

/* In dominance.c */

enum cdi_direction
{
  CDI_DOMINATORS,
  CDI_POST_DOMINATORS
};

extern dominance_info calculate_dominance_info  PARAMS ((enum cdi_direction));
extern void free_dominance_info                 PARAMS ((dominance_info));
extern basic_block nearest_common_dominator     PARAMS ((dominance_info,
                                                 basic_block, basic_block));
extern void set_immediate_dominator     PARAMS ((dominance_info,
                                                 basic_block, basic_block));
extern basic_block get_immediate_dominator      PARAMS ((dominance_info,
                                                 basic_block));
extern bool dominated_by_p      PARAMS ((dominance_info, basic_block, basic_block));
extern int get_dominated_by PARAMS ((dominance_info, basic_block, basic_block **));
extern void add_to_dominance_info PARAMS ((dominance_info, basic_block));
extern void delete_from_dominance_info PARAMS ((dominance_info, basic_block));
basic_block recount_dominator PARAMS ((dominance_info, basic_block));
extern void redirect_immediate_dominators PARAMS ((dominance_info, basic_block,
                                                 basic_block));
void iterate_fix_dominators PARAMS ((dominance_info, basic_block *, int));
extern void verify_dominators PARAMS ((dominance_info));
#endif /* GCC_BASIC_BLOCK_H */