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/* DDG - Data Dependence Graph - interface.
Copyright (C) 2004-2017 Free Software Foundation, Inc.
Contributed by Ayal Zaks and Mustafa Hagog <zaks,mustafa@il.ibm.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 GCC_DDG_H
#define GCC_DDG_H
/* For sbitmap. */
typedef struct ddg_node *ddg_node_ptr;
typedef struct ddg_edge *ddg_edge_ptr;
typedef struct ddg *ddg_ptr;
typedef struct ddg_scc *ddg_scc_ptr;
typedef struct ddg_all_sccs *ddg_all_sccs_ptr;
enum dep_type {TRUE_DEP, OUTPUT_DEP, ANTI_DEP};
enum dep_data_type {REG_OR_MEM_DEP, REG_DEP, MEM_DEP, REG_AND_MEM_DEP};
/* The following two macros enables direct access to the successors and
predecessors bitmaps held in each ddg_node. Do not make changes to
these bitmaps, unless you want to change the DDG. */
#define NODE_SUCCESSORS(x) ((x)->successors)
#define NODE_PREDECESSORS(x) ((x)->predecessors)
/* A structure that represents a node in the DDG. */
struct ddg_node
{
/* Each node has a unique CUID index. These indices increase monotonically
(according to the order of the corresponding INSN in the BB), starting
from 0 with no gaps. */
int cuid;
/* The insn represented by the node. */
rtx_insn *insn;
/* A note preceding INSN (or INSN itself), such that all insns linked
from FIRST_NOTE until INSN (inclusive of both) are moved together
when reordering the insns. This takes care of notes that should
continue to precede INSN. */
rtx_insn *first_note;
/* Incoming and outgoing dependency edges. */
ddg_edge_ptr in;
ddg_edge_ptr out;
/* Each bit corresponds to a ddg_node according to its cuid, and is
set iff the node is a successor/predecessor of "this" node. */
sbitmap successors;
sbitmap predecessors;
/* For general use by algorithms manipulating the ddg. */
union {
int count;
void *info;
} aux;
};
/* A structure that represents an edge in the DDG. */
struct ddg_edge
{
/* The source and destination nodes of the dependency edge. */
ddg_node_ptr src;
ddg_node_ptr dest;
/* TRUE, OUTPUT or ANTI dependency. */
dep_type type;
/* REG or MEM dependency. */
dep_data_type data_type;
/* Latency of the dependency. */
int latency;
/* The distance: number of loop iterations the dependency crosses. */
int distance;
/* The following two fields are used to form a linked list of the in/out
going edges to/from each node. */
ddg_edge_ptr next_in;
ddg_edge_ptr next_out;
/* For general use by algorithms manipulating the ddg. */
union {
int count;
void *info;
} aux;
};
/* This structure holds the Data Dependence Graph for a basic block. */
struct ddg
{
/* The basic block for which this DDG is built. */
basic_block bb;
/* Number of instructions in the basic block. */
int num_nodes;
/* Number of load/store instructions in the BB - statistics. */
int num_loads;
int num_stores;
/* Number of debug instructions in the BB. */
int num_debug;
/* This array holds the nodes in the graph; it is indexed by the node
cuid, which follows the order of the instructions in the BB. */
ddg_node_ptr nodes;
/* The branch closing the loop. */
ddg_node_ptr closing_branch;
/* Build dependence edges for closing_branch, when set. In certain cases,
the closing branch can be dealt with separately from the insns of the
loop, and then no such deps are needed. */
int closing_branch_deps;
/* Array and number of backarcs (edges with distance > 0) in the DDG. */
int num_backarcs;
ddg_edge_ptr *backarcs;
};
/* Holds information on an SCC (Strongly Connected Component) of the DDG. */
struct ddg_scc
{
/* A bitmap that represents the nodes of the DDG that are in the SCC. */
sbitmap nodes;
/* Array and number of backarcs (edges with distance > 0) in the SCC. */
ddg_edge_ptr *backarcs;
int num_backarcs;
/* The maximum of (total_latency/total_distance) over all cycles in SCC. */
int recurrence_length;
};
/* This structure holds the SCCs of the DDG. */
struct ddg_all_sccs
{
/* Array that holds the SCCs in the DDG, and their number. */
ddg_scc_ptr *sccs;
int num_sccs;
ddg_ptr ddg;
};
ddg_ptr create_ddg (basic_block, int closing_branch_deps);
void free_ddg (ddg_ptr);
void print_ddg (FILE *, ddg_ptr);
void vcg_print_ddg (FILE *, ddg_ptr);
void print_ddg_edge (FILE *, ddg_edge_ptr);
void print_sccs (FILE *, ddg_all_sccs_ptr, ddg_ptr);
ddg_node_ptr get_node_of_insn (ddg_ptr, rtx_insn *);
void find_successors (sbitmap result, ddg_ptr, sbitmap);
void find_predecessors (sbitmap result, ddg_ptr, sbitmap);
ddg_all_sccs_ptr create_ddg_all_sccs (ddg_ptr);
void free_ddg_all_sccs (ddg_all_sccs_ptr);
int find_nodes_on_paths (sbitmap result, ddg_ptr, sbitmap from, sbitmap to);
int longest_simple_path (ddg_ptr, int from, int to, sbitmap via);
bool autoinc_var_is_used_p (rtx_insn *, rtx_insn *);
#endif /* GCC_DDG_H */