gcc/gcc/tree-flow.h

/* Data and Control Flow Analysis for Trees.
   Copyright (C) 2001-2013 Free Software Foundation, Inc.
   Contributed by Diego Novillo <dnovillo@redhat.com>

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 3, 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 COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#ifndef _TREE_FLOW_H
#define _TREE_FLOW_H 1

#include "bitmap.h"
#include "sbitmap.h"
#include "basic-block.h"
#include "hashtab.h"
#include "gimple.h"
#include "tree-ssa-operands.h"
#include "cgraph.h"
#include "ipa-reference.h"
#include "tree-ssa-alias.h"
#include "tree-cfgcleanup.h"
#include "tree-dfa.h"
#include "tree-pretty-print.h"
#include "gimple-low.h"
#include "tree-into-ssa.h"

/* This structure is used to map a gimple statement to a label,
   or list of labels to represent transaction restart.  */

struct GTY(()) tm_restart_node {
  gimple stmt;
  tree label_or_list;
};

/* Gimple dataflow datastructure. All publicly available fields shall have
   gimple_ accessor defined in tree-flow-inline.h, all publicly modifiable
   fields should have gimple_set accessor.  */
struct GTY(()) gimple_df {
  /* A vector of all the noreturn calls passed to modify_stmt.
     cleanup_control_flow uses it to detect cases where a mid-block
     indirect call has been turned into a noreturn call.  When this
     happens, all the instructions after the call are no longer
     reachable and must be deleted as dead.  */
  vec<gimple, va_gc> *modified_noreturn_calls;

  /* Array of all SSA_NAMEs used in the function.  */
  vec<tree, va_gc> *ssa_names;

  /* Artificial variable used for the virtual operand FUD chain.  */
  tree vop;

  /* The PTA solution for the ESCAPED artificial variable.  */
  struct pt_solution escaped;

  /* A map of decls to artificial ssa-names that point to the partition
     of the decl.  */
  struct pointer_map_t * GTY((skip(""))) decls_to_pointers;

  /* Free list of SSA_NAMEs.  */
  vec<tree, va_gc> *free_ssanames;

  /* Hashtable holding definition for symbol.  If this field is not NULL, it
     means that the first reference to this variable in the function is a
     USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
     for this variable with an empty defining statement.  */
  htab_t GTY((param_is (union tree_node))) default_defs;

  /* True if there are any symbols that need to be renamed.  */
  unsigned int ssa_renaming_needed : 1;

  /* True if all virtual operands need to be renamed.  */
  unsigned int rename_vops : 1;

  /* True if the code is in ssa form.  */
  unsigned int in_ssa_p : 1;

  /* True if IPA points-to information was computed for this function.  */
  unsigned int ipa_pta : 1;

  struct ssa_operands ssa_operands;

  /* Map gimple stmt to tree label (or list of labels) for transaction
     restart and abort.  */
  htab_t GTY ((param_is (struct tm_restart_node))) tm_restart;
};

static inline int get_lineno (const_gimple);

/*---------------------------------------------------------------------------
			      Global declarations
---------------------------------------------------------------------------*/
struct int_tree_map {
  unsigned int uid;
  tree to;
};

/* Macros for showing usage statistics.  */
#define SCALE(x) ((unsigned long) ((x) < 1024*10	\
		  ? (x)					\
		  : ((x) < 1024*1024*10			\
		     ? (x) / 1024			\
		     : (x) / (1024*1024))))

#define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))

#define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))

/*---------------------------------------------------------------------------
			      OpenMP Region Tree
---------------------------------------------------------------------------*/

/* Parallel region information.  Every parallel and workshare
   directive is enclosed between two markers, the OMP_* directive
   and a corresponding OMP_RETURN statement.  */

struct omp_region
{
  /* The enclosing region.  */
  struct omp_region *outer;

  /* First child region.  */
  struct omp_region *inner;

  /* Next peer region.  */
  struct omp_region *next;

  /* Block containing the omp directive as its last stmt.  */
  basic_block entry;

  /* Block containing the OMP_RETURN as its last stmt.  */
  basic_block exit;

  /* Block containing the OMP_CONTINUE as its last stmt.  */
  basic_block cont;

  /* If this is a combined parallel+workshare region, this is a list
     of additional arguments needed by the combined parallel+workshare
     library call.  */
  vec<tree, va_gc> *ws_args;

  /* The code for the omp directive of this region.  */
  enum gimple_code type;

  /* Schedule kind, only used for OMP_FOR type regions.  */
  enum omp_clause_schedule_kind sched_kind;

  /* True if this is a combined parallel+workshare region.  */
  bool is_combined_parallel;
};

extern struct omp_region *root_omp_region;
extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
					  struct omp_region *);
extern void free_omp_regions (void);
void omp_expand_local (basic_block);
tree copy_var_decl (tree, tree, tree);

/*---------------------------------------------------------------------------
			      Function prototypes
---------------------------------------------------------------------------*/
/* In tree-cfg.c  */

/* Location to track pending stmt for edge insertion.  */
#define PENDING_STMT(e)	((e)->insns.g)

extern void delete_tree_cfg_annotations (void);
extern bool stmt_ends_bb_p (gimple);
extern bool is_ctrl_stmt (gimple);
extern bool is_ctrl_altering_stmt (gimple);
extern bool simple_goto_p (gimple);
extern bool stmt_can_make_abnormal_goto (gimple);
extern basic_block single_noncomplex_succ (basic_block bb);
extern void gimple_dump_bb (FILE *, basic_block, int, int);
extern void gimple_debug_bb (basic_block);
extern basic_block gimple_debug_bb_n (int);
extern void gimple_dump_cfg (FILE *, int);
extern void gimple_debug_cfg (int);
extern void dump_cfg_stats (FILE *);
extern void dot_cfg (void);
extern void debug_cfg_stats (void);
extern void debug_loops (int);
extern void debug_loop (struct loop *, int);
extern void debug (struct loop &ref);
extern void debug (struct loop *ptr);
extern void debug_verbose (struct loop &ref);
extern void debug_verbose (struct loop *ptr);
extern void debug_loop_num (unsigned, int);
extern void print_loops (FILE *, int);
extern void print_loops_bb (FILE *, basic_block, int, int);
extern void cleanup_dead_labels (void);
extern void group_case_labels_stmt (gimple);
extern void group_case_labels (void);
extern gimple first_stmt (basic_block);
extern gimple last_stmt (basic_block);
extern gimple last_and_only_stmt (basic_block);
extern edge find_taken_edge (basic_block, tree);
extern basic_block label_to_block_fn (struct function *, tree);
#define label_to_block(t) (label_to_block_fn (cfun, t))
extern void notice_special_calls (gimple);
extern void clear_special_calls (void);
extern void verify_gimple_in_seq (gimple_seq);
extern void verify_gimple_in_cfg (struct function *);
extern tree gimple_block_label (basic_block);
extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
					basic_block *, bool);
extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
				      basic_block *);
extern void gather_blocks_in_sese_region (basic_block entry, basic_block exit,
					  vec<basic_block> *bbs_p);
extern void add_phi_args_after_copy_bb (basic_block);
extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
extern bool gimple_purge_dead_eh_edges (basic_block);
extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
extern bool gimple_purge_all_dead_abnormal_call_edges (const_bitmap);
extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
			     tree, tree);
extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
			     tree, tree, tree);
extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
			     tree, tree, tree, tree);
extern void init_empty_tree_cfg (void);
extern void init_empty_tree_cfg_for_function (struct function *);
extern void fold_cond_expr_cond (void);
extern void make_abnormal_goto_edges (basic_block, bool);
extern void replace_uses_by (tree, tree);
extern void start_recording_case_labels (void);
extern void end_recording_case_labels (void);
extern basic_block move_sese_region_to_fn (struct function *, basic_block,
				           basic_block, tree);
void remove_edge_and_dominated_blocks (edge);
bool tree_node_can_be_shared (tree);

/* In tree-ssa-dom.c  */
extern void dump_dominator_optimization_stats (FILE *);
extern void debug_dominator_optimization_stats (void);
int loop_depth_of_name (tree);
tree degenerate_phi_result (gimple);
bool simple_iv_increment_p (gimple);

/* In tree-ssa-loop-ch.c  */
bool do_while_loop_p (struct loop *);

/* Affine iv.  */

typedef struct
{
  /* Iv = BASE + STEP * i.  */
  tree base, step;

  /* True if this iv does not overflow.  */
  bool no_overflow;
} affine_iv;

/* Description of number of iterations of a loop.  All the expressions inside
   the structure can be evaluated at the end of the loop's preheader
   (and due to ssa form, also anywhere inside the body of the loop).  */

struct tree_niter_desc
{
  tree assumptions;	/* The boolean expression.  If this expression evaluates
			   to false, then the other fields in this structure
			   should not be used; there is no guarantee that they
			   will be correct.  */
  tree may_be_zero;	/* The boolean expression.  If it evaluates to true,
			   the loop will exit in the first iteration (i.e.
			   its latch will not be executed), even if the niter
			   field says otherwise.  */
  tree niter;		/* The expression giving the number of iterations of
			   a loop (provided that assumptions == true and
			   may_be_zero == false), more precisely the number
			   of executions of the latch of the loop.  */
  double_int max;	/* The upper bound on the number of iterations of
			   the loop.  */

  /* The simplified shape of the exit condition.  The loop exits if
     CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
     LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
     LE_EXPR and negative if CMP is GE_EXPR.  This information is used
     by loop unrolling.  */
  affine_iv control;
  tree bound;
  enum tree_code cmp;
};

/* In tree-ssa-phiopt.c */
bool empty_block_p (basic_block);
basic_block *blocks_in_phiopt_order (void);
bool nonfreeing_call_p (gimple);

/* In tree-ssa-loop*.c  */

unsigned int tree_ssa_lim (void);
unsigned int tree_ssa_unswitch_loops (void);
unsigned int canonicalize_induction_variables (void);
unsigned int tree_unroll_loops_completely (bool, bool);
unsigned int tree_ssa_prefetch_arrays (void);
void tree_ssa_iv_optimize (void);
unsigned tree_predictive_commoning (void);
tree canonicalize_loop_ivs (struct loop *, tree *, bool);
bool parallelize_loops (void);

bool loop_only_exit_p (const struct loop *, const_edge);
bool number_of_iterations_exit (struct loop *, edge,
				struct tree_niter_desc *niter, bool,
				bool every_iteration = true);
tree find_loop_niter (struct loop *, edge *);
tree loop_niter_by_eval (struct loop *, edge);
tree find_loop_niter_by_eval (struct loop *, edge *);
void estimate_numbers_of_iterations (void);
bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);

bool nowrap_type_p (tree);
enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
enum ev_direction scev_direction (const_tree);

void free_numbers_of_iterations_estimates (void);
void free_numbers_of_iterations_estimates_loop (struct loop *);
void rewrite_into_loop_closed_ssa (bitmap, unsigned);
void verify_loop_closed_ssa (bool);
bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
		tree *, tree *);
basic_block split_loop_exit_edge (edge);
void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
				     bool *);
basic_block ip_end_pos (struct loop *);
basic_block ip_normal_pos (struct loop *);
bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
					 unsigned int, sbitmap,
					 edge, vec<edge> *,
					 int);
struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
tree expand_simple_operations (tree);
void substitute_in_loop_info (struct loop *, tree, tree);
edge single_dom_exit (struct loop *);
bool can_unroll_loop_p (struct loop *loop, unsigned factor,
			struct tree_niter_desc *niter);
void tree_unroll_loop (struct loop *, unsigned,
		       edge, struct tree_niter_desc *);
typedef void (*transform_callback)(struct loop *, void *);
void tree_transform_and_unroll_loop (struct loop *, unsigned,
				     edge, struct tree_niter_desc *,
				     transform_callback, void *);
bool contains_abnormal_ssa_name_p (tree);
bool stmt_dominates_stmt_p (gimple, gimple);

/* In tree-ssa-dce.c */
void mark_virtual_operand_for_renaming (tree);
void mark_virtual_phi_result_for_renaming (gimple);

/* In tree-ssa-threadedge.c */
extern void threadedge_initialize_values (void);
extern void threadedge_finalize_values (void);
extern vec<tree> ssa_name_values;
#define SSA_NAME_VALUE(x) \
    (SSA_NAME_VERSION (x) < ssa_name_values.length () \
     ? ssa_name_values[SSA_NAME_VERSION (x)] \
     : NULL_TREE)
extern void set_ssa_name_value (tree, tree);
extern bool potentially_threadable_block (basic_block);
extern void thread_across_edge (gimple, edge, bool,
				vec<tree> *, tree (*) (gimple, gimple));
extern void propagate_threaded_block_debug_into (basic_block, basic_block);

/* In tree-ssa-loop-im.c  */
/* The possibilities of statement movement.  */

enum move_pos
  {
    MOVE_IMPOSSIBLE,		/* No movement -- side effect expression.  */
    MOVE_PRESERVE_EXECUTION,	/* Must not cause the non-executed statement
				   become executed -- memory accesses, ... */
    MOVE_POSSIBLE		/* Unlimited movement.  */
  };
extern enum move_pos movement_possibility (gimple);
char *get_lsm_tmp_name (tree, unsigned);

/* In tree-flow-inline.h  */
static inline bool unmodifiable_var_p (const_tree);
static inline bool ref_contains_array_ref (const_tree);

/* In tree-eh.c  */
extern void make_eh_edges (gimple);
extern bool make_eh_dispatch_edges (gimple);
extern edge redirect_eh_edge (edge, basic_block);
extern void redirect_eh_dispatch_edge (gimple, edge, basic_block);
extern bool stmt_could_throw_p (gimple);
extern bool stmt_can_throw_internal (gimple);
extern bool stmt_can_throw_external (gimple);
extern void add_stmt_to_eh_lp_fn (struct function *, gimple, int);
extern void add_stmt_to_eh_lp (gimple, int);
extern bool remove_stmt_from_eh_lp (gimple);
extern bool remove_stmt_from_eh_lp_fn (struct function *, gimple);
extern int lookup_stmt_eh_lp_fn (struct function *, gimple);
extern int lookup_stmt_eh_lp (gimple);
extern bool maybe_clean_eh_stmt_fn (struct function *, gimple);
extern bool maybe_clean_eh_stmt (gimple);
extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
extern bool maybe_duplicate_eh_stmt_fn (struct function *, gimple,
					struct function *, gimple,
					struct pointer_map_t *, int);
extern bool maybe_duplicate_eh_stmt (gimple, gimple);
extern bool verify_eh_edges (gimple);
extern bool verify_eh_dispatch_edge (gimple);
extern void maybe_remove_unreachable_handlers (void);

/* In tree-ssa-pre.c  */
void debug_value_expressions (unsigned int);

/* In tree-loop-linear.c  */
extern void linear_transform_loops (void);
extern unsigned perfect_loop_nest_depth (struct loop *);

/* In graphite.c  */
extern void graphite_transform_loops (void);

/* In tree-data-ref.c  */
extern void tree_check_data_deps (void);

/* In tree-ssa-loop-ivopts.c  */
bool expr_invariant_in_loop_p (struct loop *, tree);
bool stmt_invariant_in_loop_p (struct loop *, gimple);
struct loop *outermost_invariant_loop_for_expr (struct loop *, tree);
bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode,
				      addr_space_t);
bool may_be_nonaddressable_p (tree expr);

/* In gimplify.c  */
tree force_gimple_operand_1 (tree, gimple_seq *, gimple_predicate, tree);
tree force_gimple_operand (tree, gimple_seq *, bool, tree);
tree force_gimple_operand_gsi_1 (gimple_stmt_iterator *, tree,
				 gimple_predicate, tree,
				 bool, enum gsi_iterator_update);
tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
			       bool, enum gsi_iterator_update);
tree gimple_fold_indirect_ref (tree);

/* In tree-ssa-live.c */
extern void remove_unused_locals (void);
extern void dump_scope_blocks (FILE *, int);
extern void debug_scope_blocks (int);
extern void debug_scope_block (tree, int);

/* In tree-ssa-address.c  */

/* Description of a memory address.  */

struct mem_address
{
  tree symbol, base, index, step, offset;
};

struct affine_tree_combination;
tree create_mem_ref (gimple_stmt_iterator *, tree,
		     struct affine_tree_combination *, tree, tree, tree, bool);
rtx addr_for_mem_ref (struct mem_address *, addr_space_t, bool);
void get_address_description (tree, struct mem_address *);
tree maybe_fold_tmr (tree);

unsigned int execute_fixup_cfg (void);

/* In ipa-pure-const.c  */
void warn_function_noreturn (tree);

/* In tree-parloops.c  */
bool parallelized_function_p (tree);

#include "tree-flow-inline.h"

#endif /* _TREE_FLOW_H  */