basic-block.h   [plain text]


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

This file is part of GNU CC.

GNU CC 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.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */


#include "bitmap.h"
#include "sbitmap.h"
#include "varray.h"

typedef bitmap regset;		/* Head of register set linked list.  */

/* 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)

/* `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)

/* 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.  */
#define REG_SET_TO_HARD_REG_SET(TO, FROM)				\
do {									\
  int i_;								\
  CLEAR_HARD_REG_SET (TO);						\
  for (i_ = 0; i_ < FIRST_PSEUDO_REGISTER; i_++)			\
    if (REGNO_REG_SET_P (FROM, i_))					\
      SET_HARD_REG_BIT (TO, i_);					\
} 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)

/* Allocate a register set with alloca.  */
#define ALLOCA_REG_SET() BITMAP_ALLOCA ()

/* 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) 

/* 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 */
} *edge;

#define EDGE_FALLTHRU		1
#define EDGE_CRITICAL		2
#define EDGE_ABNORMAL		4
#define EDGE_ABNORMAL_CALL	8
#define EDGE_EH			16
#define EDGE_FAKE		32


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

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

  /* Liveness info.  */
  regset local_set;
  regset global_live_at_start;
  regset global_live_at_end;

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

  /* The index of this block.  */
  int index;
  /* The loop depth of this block plus one.  */
  int loop_depth;
} *basic_block;

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

extern int n_basic_blocks;

/* 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)))

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

extern regset regs_live_at_setjmp;

/* 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)

/* List of integers.
   These are used for storing things like predecessors, etc.

   This scheme isn't very space efficient, especially on 64 bit machines.
   The interface is designed so that the implementation can be replaced with
   something more efficient if desirable.  */

typedef struct int_list {
  struct int_list *next;
  int val;
} int_list;

typedef int_list *int_list_ptr;

/* Integer list elements are allocated in blocks to reduce the frequency
   of calls to malloc and to reduce the associated space overhead.  */

typedef struct int_list_block {
  struct int_list_block *next;
  int nodes_left;
#define INT_LIST_NODES_IN_BLK 500
  struct int_list nodes[INT_LIST_NODES_IN_BLK];
} int_list_block;

/* Given a pointer to the list, return pointer to first element.  */
#define INT_LIST_FIRST(il) (il)

/* Given a pointer to a list element, return pointer to next element.  */
#define INT_LIST_NEXT(p) ((p)->next)

/* Return non-zero if P points to the end of the list.  */
#define INT_LIST_END(p) ((p) == NULL)

/* Return element pointed to by P.  */
#define INT_LIST_VAL(p) ((p)->val)

#define INT_LIST_SET_VAL(p, new_val) ((p)->val = (new_val))

extern void free_int_list               PROTO ((int_list_block **));

/* Stuff for recording basic block info.  */

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

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

/* 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])

/* from flow.c */
extern void free_regset_vector		PROTO ((regset *, int nelts));

extern varray_type basic_block_for_insn;
#define BLOCK_FOR_INSN(INSN)  VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
#define BLOCK_NUM(INSN)	      (BLOCK_FOR_INSN (INSN)->index + 0)

extern void set_block_for_insn		PROTO ((rtx, basic_block));

extern void dump_bb_data		PROTO ((FILE *, int_list_ptr *,
						int_list_ptr *, int));
extern void free_bb_mem			PROTO ((void));
extern void free_basic_block_vars	PROTO ((int));

extern basic_block split_edge		PROTO ((edge));
extern void insert_insn_on_edge		PROTO ((rtx, edge));
extern void commit_edge_insertions	PROTO ((void));

extern void compute_preds_succs		PROTO ((int_list_ptr *, int_list_ptr *,
						int *, int *));
extern void compute_dominators		PROTO ((sbitmap *, sbitmap *,
						int_list_ptr *,
						int_list_ptr *));
extern void compute_immediate_dominators	PROTO ((int *, sbitmap *));

/* In lcm.c */
extern void pre_lcm 			PROTO ((int, int, int_list_ptr *,
						int_list_ptr *,
						sbitmap *, sbitmap *,
						sbitmap *, sbitmap *));
extern void pre_rev_lcm 		PROTO ((int, int, int_list_ptr *,
						int_list_ptr *,
						sbitmap *, sbitmap *,
						sbitmap *, sbitmap *));