1 /* DDG - Data Dependence Graph - interface. 2 Copyright (C) 2004 3 Free Software Foundation, Inc. 4 Contributed by Ayal Zaks and Mustafa Hagog <zaks,mustafa@il.ibm.com> 5 6 This file is part of GCC. 7 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 2, or (at your option) any later 11 version. 12 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 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING. If not, write to the Free 20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 21 02110-1301, USA. */ 22 23 #ifndef GCC_DDG_H 24 #define GCC_DDG_H 25 26 /* For sbitmap. */ 27 #include "sbitmap.h" 28 /* For basic_block. */ 29 #include "basic-block.h" 30 /* For struct df. */ 31 #include "df.h" 32 33 typedef struct ddg_node *ddg_node_ptr; 34 typedef struct ddg_edge *ddg_edge_ptr; 35 typedef struct ddg *ddg_ptr; 36 typedef struct ddg_scc *ddg_scc_ptr; 37 typedef struct ddg_all_sccs *ddg_all_sccs_ptr; 38 39 typedef enum {TRUE_DEP, OUTPUT_DEP, ANTI_DEP} dep_type; 40 typedef enum {REG_OR_MEM_DEP, REG_DEP, MEM_DEP, REG_AND_MEM_DEP} 41 dep_data_type; 42 43 /* The following two macros enables direct access to the successors and 44 predecessors bitmaps held in each ddg_node. Do not make changes to 45 these bitmaps, unless you want to change the DDG. */ 46 #define NODE_SUCCESSORS(x) ((x)->successors) 47 #define NODE_PREDECESSORS(x) ((x)->predecessors) 48 49 /* A structure that represents a node in the DDG. */ 50 struct ddg_node 51 { 52 /* Each node has a unique CUID index. These indices increase monotonically 53 (according to the order of the corresponding INSN in the BB), starting 54 from 0 with no gaps. */ 55 int cuid; 56 57 /* The insn represented by the node. */ 58 rtx insn; 59 60 /* A note preceding INSN (or INSN itself), such that all insns linked 61 from FIRST_NOTE until INSN (inclusive of both) are moved together 62 when reordering the insns. This takes care of notes that should 63 continue to precede INSN. */ 64 rtx first_note; 65 66 /* Incoming and outgoing dependency edges. */ 67 ddg_edge_ptr in; 68 ddg_edge_ptr out; 69 70 /* Each bit corresponds to a ddg_node according to its cuid, and is 71 set iff the node is a successor/predecessor of "this" node. */ 72 sbitmap successors; 73 sbitmap predecessors; 74 75 /* For general use by algorithms manipulating the ddg. */ 76 union { 77 int count; 78 void *info; 79 } aux; 80 }; 81 82 /* A structure that represents an edge in the DDG. */ 83 struct ddg_edge 84 { 85 /* The source and destination nodes of the dependency edge. */ 86 ddg_node_ptr src; 87 ddg_node_ptr dest; 88 89 /* TRUE, OUTPUT or ANTI dependency. */ 90 dep_type type; 91 92 /* REG or MEM dependency. */ 93 dep_data_type data_type; 94 95 /* Latency of the dependency. */ 96 int latency; 97 98 /* The distance: number of loop iterations the dependency crosses. */ 99 int distance; 100 101 /* The following two fields are used to form a linked list of the in/out 102 going edges to/from each node. */ 103 ddg_edge_ptr next_in; 104 ddg_edge_ptr next_out; 105 106 /* For general use by algorithms manipulating the ddg. */ 107 union { 108 int count; 109 void *info; 110 } aux; 111 }; 112 113 /* This structure holds the Data Dependence Graph for a basic block. */ 114 struct ddg 115 { 116 /* The basic block for which this DDG is built. */ 117 basic_block bb; 118 119 /* Number of instructions in the basic block. */ 120 int num_nodes; 121 122 /* Number of load/store instructions in the BB - statistics. */ 123 int num_loads; 124 int num_stores; 125 126 /* This array holds the nodes in the graph; it is indexed by the node 127 cuid, which follows the order of the instructions in the BB. */ 128 ddg_node_ptr nodes; 129 130 /* The branch closing the loop. */ 131 ddg_node_ptr closing_branch; 132 133 /* Build dependence edges for closing_branch, when set. In certain cases, 134 the closing branch can be dealt with separately from the insns of the 135 loop, and then no such deps are needed. */ 136 int closing_branch_deps; 137 138 /* Array and number of backarcs (edges with distance > 0) in the DDG. */ 139 ddg_edge_ptr *backarcs; 140 int num_backarcs; 141 }; 142 143 144 /* Holds information on an SCC (Strongly Connected Component) of the DDG. */ 145 struct ddg_scc 146 { 147 /* A bitmap that represents the nodes of the DDG that are in the SCC. */ 148 sbitmap nodes; 149 150 /* Array and number of backarcs (edges with distance > 0) in the SCC. */ 151 ddg_edge_ptr *backarcs; 152 int num_backarcs; 153 154 /* The maximum of (total_latency/total_distance) over all cycles in SCC. */ 155 int recurrence_length; 156 }; 157 158 /* This structure holds the SCCs of the DDG. */ 159 struct ddg_all_sccs 160 { 161 /* Array that holds the SCCs in the DDG, and their number. */ 162 ddg_scc_ptr *sccs; 163 int num_sccs; 164 165 ddg_ptr ddg; 166 }; 167 168 169 ddg_ptr create_ddg (basic_block, struct df *, int closing_branch_deps); 170 void free_ddg (ddg_ptr); 171 172 void print_ddg (FILE *, ddg_ptr); 173 void vcg_print_ddg (FILE *, ddg_ptr); 174 void print_ddg_edge (FILE *, ddg_edge_ptr); 175 176 ddg_node_ptr get_node_of_insn (ddg_ptr, rtx); 177 178 void find_successors (sbitmap result, ddg_ptr, sbitmap); 179 void find_predecessors (sbitmap result, ddg_ptr, sbitmap); 180 181 ddg_all_sccs_ptr create_ddg_all_sccs (ddg_ptr); 182 void free_ddg_all_sccs (ddg_all_sccs_ptr); 183 184 int find_nodes_on_paths (sbitmap result, ddg_ptr, sbitmap from, sbitmap to); 185 int longest_simple_path (ddg_ptr, int from, int to, sbitmap via); 186 187 #endif /* GCC_DDG_H */ 188