1 /* DDG - Data Dependence Graph - interface.
2 Copyright (C) 2004, 2005, 2006, 2007, 2008
3 Free Software Foundation, Inc.
4 Contributed by Ayal Zaks and Mustafa Hagog <zaks,mustafa@il.ibm.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
27 /* For basic_block. */
28 #include "basic-block.h"
31 typedef struct ddg_node *ddg_node_ptr;
32 typedef struct ddg_edge *ddg_edge_ptr;
33 typedef struct ddg *ddg_ptr;
34 typedef struct ddg_scc *ddg_scc_ptr;
35 typedef struct ddg_all_sccs *ddg_all_sccs_ptr;
37 typedef enum {TRUE_DEP, OUTPUT_DEP, ANTI_DEP} dep_type;
38 typedef enum {REG_OR_MEM_DEP, REG_DEP, MEM_DEP, REG_AND_MEM_DEP}
41 /* The following two macros enables direct access to the successors and
42 predecessors bitmaps held in each ddg_node. Do not make changes to
43 these bitmaps, unless you want to change the DDG. */
44 #define NODE_SUCCESSORS(x) ((x)->successors)
45 #define NODE_PREDECESSORS(x) ((x)->predecessors)
47 /* A structure that represents a node in the DDG. */
50 /* Each node has a unique CUID index. These indices increase monotonically
51 (according to the order of the corresponding INSN in the BB), starting
52 from 0 with no gaps. */
55 /* The insn represented by the node. */
58 /* A note preceding INSN (or INSN itself), such that all insns linked
59 from FIRST_NOTE until INSN (inclusive of both) are moved together
60 when reordering the insns. This takes care of notes that should
61 continue to precede INSN. */
64 /* Incoming and outgoing dependency edges. */
68 /* Each bit corresponds to a ddg_node according to its cuid, and is
69 set iff the node is a successor/predecessor of "this" node. */
73 /* For general use by algorithms manipulating the ddg. */
80 /* A structure that represents an edge in the DDG. */
83 /* The source and destination nodes of the dependency edge. */
87 /* TRUE, OUTPUT or ANTI dependency. */
90 /* REG or MEM dependency. */
91 dep_data_type data_type;
93 /* Latency of the dependency. */
96 /* The distance: number of loop iterations the dependency crosses. */
99 /* The following two fields are used to form a linked list of the in/out
100 going edges to/from each node. */
101 ddg_edge_ptr next_in;
102 ddg_edge_ptr next_out;
104 /* For general use by algorithms manipulating the ddg. */
111 /* This structure holds the Data Dependence Graph for a basic block. */
114 /* The basic block for which this DDG is built. */
117 /* Number of instructions in the basic block. */
120 /* Number of load/store instructions in the BB - statistics. */
124 /* Number of debug instructions in the BB. */
127 /* This array holds the nodes in the graph; it is indexed by the node
128 cuid, which follows the order of the instructions in the BB. */
131 /* The branch closing the loop. */
132 ddg_node_ptr closing_branch;
134 /* Build dependence edges for closing_branch, when set. In certain cases,
135 the closing branch can be dealt with separately from the insns of the
136 loop, and then no such deps are needed. */
137 int closing_branch_deps;
139 /* Array and number of backarcs (edges with distance > 0) in the DDG. */
141 ddg_edge_ptr *backarcs;
145 /* Holds information on an SCC (Strongly Connected Component) of the DDG. */
148 /* A bitmap that represents the nodes of the DDG that are in the SCC. */
151 /* Array and number of backarcs (edges with distance > 0) in the SCC. */
152 ddg_edge_ptr *backarcs;
155 /* The maximum of (total_latency/total_distance) over all cycles in SCC. */
156 int recurrence_length;
159 /* This structure holds the SCCs of the DDG. */
162 /* Array that holds the SCCs in the DDG, and their number. */
170 ddg_ptr create_ddg (basic_block, int closing_branch_deps);
171 void free_ddg (ddg_ptr);
173 void print_ddg (FILE *, ddg_ptr);
174 void vcg_print_ddg (FILE *, ddg_ptr);
175 void print_ddg_edge (FILE *, ddg_edge_ptr);
176 void print_sccs (FILE *, ddg_all_sccs_ptr, ddg_ptr);
178 ddg_node_ptr get_node_of_insn (ddg_ptr, rtx);
180 void find_successors (sbitmap result, ddg_ptr, sbitmap);
181 void find_predecessors (sbitmap result, ddg_ptr, sbitmap);
183 ddg_all_sccs_ptr create_ddg_all_sccs (ddg_ptr);
184 void free_ddg_all_sccs (ddg_all_sccs_ptr);
186 int find_nodes_on_paths (sbitmap result, ddg_ptr, sbitmap from, sbitmap to);
187 int longest_simple_path (ddg_ptr, int from, int to, sbitmap via);
189 #endif /* GCC_DDG_H */