1 | /* DDG - Data Dependence Graph - interface. |
2 | Copyright (C) 2004-2023 Free Software Foundation, Inc. |
3 | Contributed by Ayal Zaks and Mustafa Hagog <zaks,mustafa@il.ibm.com> |
4 | |
5 | This file is part of GCC. |
6 | |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free |
9 | Software Foundation; either version 3, or (at your option) any later |
10 | version. |
11 | |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
15 | for more details. |
16 | |
17 | You should have received a copy of the GNU General Public License |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ |
20 | |
21 | #ifndef GCC_DDG_H |
22 | #define GCC_DDG_H |
23 | |
24 | /* For sbitmap. */ |
25 | |
26 | typedef struct ddg_node *ddg_node_ptr; |
27 | typedef struct ddg_edge *ddg_edge_ptr; |
28 | typedef struct ddg *ddg_ptr; |
29 | typedef struct ddg_scc *ddg_scc_ptr; |
30 | typedef struct ddg_all_sccs *ddg_all_sccs_ptr; |
31 | |
32 | enum dep_type {TRUE_DEP, OUTPUT_DEP, ANTI_DEP}; |
33 | enum dep_data_type {REG_OR_MEM_DEP, REG_DEP, MEM_DEP, REG_AND_MEM_DEP}; |
34 | |
35 | /* The following two macros enables direct access to the successors and |
36 | predecessors bitmaps held in each ddg_node. Do not make changes to |
37 | these bitmaps, unless you want to change the DDG. */ |
38 | #define NODE_SUCCESSORS(x) ((x)->successors) |
39 | #define NODE_PREDECESSORS(x) ((x)->predecessors) |
40 | |
41 | /* A structure that represents a node in the DDG. */ |
42 | struct ddg_node |
43 | { |
44 | /* Each node has a unique CUID index. These indices increase monotonically |
45 | (according to the order of the corresponding INSN in the BB), starting |
46 | from 0 with no gaps. */ |
47 | int cuid; |
48 | |
49 | /* The insn represented by the node. */ |
50 | rtx_insn *insn; |
51 | |
52 | /* A note preceding INSN (or INSN itself), such that all insns linked |
53 | from FIRST_NOTE until INSN (inclusive of both) are moved together |
54 | when reordering the insns. This takes care of notes that should |
55 | continue to precede INSN. */ |
56 | rtx_insn *first_note; |
57 | |
58 | /* Incoming and outgoing dependency edges. */ |
59 | ddg_edge_ptr in; |
60 | ddg_edge_ptr out; |
61 | |
62 | /* Each bit corresponds to a ddg_node according to its cuid, and is |
63 | set iff the node is a successor/predecessor of "this" node. */ |
64 | sbitmap successors; |
65 | sbitmap predecessors; |
66 | |
67 | /* Temporary array used for Floyd-Warshall algorithm to find |
68 | scc recurrence length. */ |
69 | int *max_dist; |
70 | |
71 | /* For general use by algorithms manipulating the ddg. */ |
72 | union { |
73 | int count; |
74 | void *info; |
75 | } aux; |
76 | }; |
77 | |
78 | /* A structure that represents an edge in the DDG. */ |
79 | struct ddg_edge |
80 | { |
81 | /* The source and destination nodes of the dependency edge. */ |
82 | ddg_node_ptr src; |
83 | ddg_node_ptr dest; |
84 | |
85 | /* TRUE, OUTPUT or ANTI dependency. */ |
86 | dep_type type; |
87 | |
88 | /* REG or MEM dependency. */ |
89 | dep_data_type data_type; |
90 | |
91 | /* Latency of the dependency. */ |
92 | int latency; |
93 | |
94 | /* The distance: number of loop iterations the dependency crosses. */ |
95 | int distance; |
96 | |
97 | /* The following two fields are used to form a linked list of the in/out |
98 | going edges to/from each node. */ |
99 | ddg_edge_ptr next_in; |
100 | ddg_edge_ptr next_out; |
101 | |
102 | /* Is true when edge is already in scc. */ |
103 | bool in_scc; |
104 | }; |
105 | |
106 | /* This structure holds the Data Dependence Graph for a basic block. */ |
107 | struct ddg |
108 | { |
109 | /* The basic block for which this DDG is built. */ |
110 | basic_block bb; |
111 | |
112 | /* Number of instructions in the basic block. */ |
113 | int num_nodes; |
114 | |
115 | /* Number of load/store instructions in the BB - statistics. */ |
116 | int num_loads; |
117 | int num_stores; |
118 | |
119 | /* This array holds the nodes in the graph; it is indexed by the node |
120 | cuid, which follows the order of the instructions in the BB. */ |
121 | ddg_node_ptr nodes; |
122 | |
123 | /* The branch closing the loop. */ |
124 | ddg_node_ptr closing_branch; |
125 | |
126 | /* Build dependence edges for closing_branch, when set. In certain cases, |
127 | the closing branch can be dealt with separately from the insns of the |
128 | loop, and then no such deps are needed. */ |
129 | int closing_branch_deps; |
130 | |
131 | /* Array and number of backarcs (edges with distance > 0) in the DDG. */ |
132 | int num_backarcs; |
133 | ddg_edge_ptr *backarcs; |
134 | }; |
135 | |
136 | |
137 | /* Holds information on an SCC (Strongly Connected Component) of the DDG. */ |
138 | struct ddg_scc |
139 | { |
140 | /* A bitmap that represents the nodes of the DDG that are in the SCC. */ |
141 | sbitmap nodes; |
142 | |
143 | /* Array and number of backarcs (edges with distance > 0) in the SCC. */ |
144 | ddg_edge_ptr *backarcs; |
145 | int num_backarcs; |
146 | |
147 | /* The maximum of (total_latency/total_distance) over all cycles in SCC. */ |
148 | int recurrence_length; |
149 | }; |
150 | |
151 | /* This structure holds the SCCs of the DDG. */ |
152 | struct ddg_all_sccs |
153 | { |
154 | /* Array that holds the SCCs in the DDG, and their number. */ |
155 | ddg_scc_ptr *sccs; |
156 | int num_sccs; |
157 | |
158 | ddg_ptr ddg; |
159 | }; |
160 | |
161 | |
162 | ddg_ptr create_ddg (basic_block, int closing_branch_deps); |
163 | void free_ddg (ddg_ptr); |
164 | |
165 | void print_ddg (FILE *, ddg_ptr); |
166 | void vcg_print_ddg (FILE *, ddg_ptr); |
167 | void print_ddg_edge (FILE *, ddg_edge_ptr); |
168 | void print_sccs (FILE *, ddg_all_sccs_ptr, ddg_ptr); |
169 | |
170 | ddg_node_ptr get_node_of_insn (ddg_ptr, rtx_insn *); |
171 | |
172 | void find_successors (sbitmap result, ddg_ptr, sbitmap); |
173 | void find_predecessors (sbitmap result, ddg_ptr, sbitmap); |
174 | |
175 | ddg_all_sccs_ptr create_ddg_all_sccs (ddg_ptr); |
176 | void free_ddg_all_sccs (ddg_all_sccs_ptr); |
177 | |
178 | int find_nodes_on_paths (sbitmap result, ddg_ptr, sbitmap from, sbitmap to); |
179 | |
180 | bool autoinc_var_is_used_p (rtx_insn *, rtx_insn *); |
181 | |
182 | #endif /* GCC_DDG_H */ |
183 | |