gcc/ddg.h

   1 /* DDG - Data Dependence Graph - interface.
   2    Copyright (C) 2004-2013 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 #include "sbitmap.h"
  26 /* For basic_block.  */
  27 #include "basic-block.h"
  28 #include "df.h"
  29
  30 typedef struct ddg_node *ddg_node_ptr;
  31 typedef struct ddg_edge *ddg_edge_ptr;
  32 typedef struct ddg *ddg_ptr;
  33 typedef struct ddg_scc *ddg_scc_ptr;
  34 typedef struct ddg_all_sccs *ddg_all_sccs_ptr;
  35
  36 typedef enum {TRUE_DEP, OUTPUT_DEP, ANTI_DEP} dep_type;
  37 typedef enum {REG_OR_MEM_DEP, REG_DEP, MEM_DEP, REG_AND_MEM_DEP}
  38              dep_data_type;
  39
  40 /* The following two macros enables direct access to the successors and
  41    predecessors bitmaps held in each ddg_node.  Do not make changes to
  42    these bitmaps, unless you want to change the DDG.  */
  43 #define NODE_SUCCESSORS(x)  ((x)->successors)
  44 #define NODE_PREDECESSORS(x)  ((x)->predecessors)
  45
  46 /* A structure that represents a node in the DDG.  */
  47 struct ddg_node
  48 {
  49   /* Each node has a unique CUID index.  These indices increase monotonically
  50      (according to the order of the corresponding INSN in the BB), starting
  51      from 0 with no gaps.  */
  52   int cuid;
  53
  54   /* The insn represented by the node.  */
  55   rtx insn;
  56
  57   /* A note preceding INSN (or INSN itself), such that all insns linked
  58      from FIRST_NOTE until INSN (inclusive of both) are moved together
  59      when reordering the insns.  This takes care of notes that should
  60      continue to precede INSN.  */
  61   rtx first_note;
  62
  63   /* Incoming and outgoing dependency edges.  */
  64   ddg_edge_ptr in;
  65   ddg_edge_ptr out;
  66
  67   /* Each bit corresponds to a ddg_node according to its cuid, and is
  68      set iff the node is a successor/predecessor of "this" node.  */
  69   sbitmap successors;
  70   sbitmap predecessors;
  71
  72   /* For general use by algorithms manipulating the ddg.  */
  73   union {
  74     int count;
  75     void *info;
  76   } aux;
  77 };
  78
  79 /* A structure that represents an edge in the DDG.  */
  80 struct ddg_edge
  81 {
  82   /* The source and destination nodes of the dependency edge.  */
  83   ddg_node_ptr src;
  84   ddg_node_ptr dest;
  85
  86   /* TRUE, OUTPUT or ANTI dependency.  */
  87   dep_type type;
  88
  89   /* REG or MEM dependency.  */
  90   dep_data_type data_type;
  91
  92   /* Latency of the dependency.  */
  93   int latency;
  94
  95   /* The distance: number of loop iterations the dependency crosses.  */
  96   int distance;
  97
  98   /* The following two fields are used to form a linked list of the in/out
  99      going edges to/from each node.  */
 100   ddg_edge_ptr next_in;
 101   ddg_edge_ptr next_out;
 102
 103   /* For general use by algorithms manipulating the ddg.  */
 104   union {
 105     int count;
 106     void *info;
 107   } aux;
 108 };
 109
 110 /* This structure holds the Data Dependence Graph for a basic block.  */
 111 struct ddg
 112 {
 113   /* The basic block for which this DDG is built.  */
 114   basic_block bb;
 115
 116   /* Number of instructions in the basic block.  */
 117   int num_nodes;
 118
 119   /* Number of load/store instructions in the BB - statistics.  */
 120   int num_loads;
 121   int num_stores;
 122
 123   /* Number of debug instructions in the BB.  */
 124   int num_debug;
 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   int num_backarcs;
 140   ddg_edge_ptr *backarcs;
 141 };
 142
 143 \f
 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 \f
 169 ddg_ptr create_ddg (basic_block, 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 void print_sccs (FILE *, ddg_all_sccs_ptr, ddg_ptr);
 176
 177 ddg_node_ptr get_node_of_insn (ddg_ptr, rtx);
 178
 179 void find_successors (sbitmap result, ddg_ptr, sbitmap);
 180 void find_predecessors (sbitmap result, ddg_ptr, sbitmap);
 181
 182 ddg_all_sccs_ptr create_ddg_all_sccs (ddg_ptr);
 183 void free_ddg_all_sccs (ddg_all_sccs_ptr);
 184
 185 int find_nodes_on_paths (sbitmap result, ddg_ptr, sbitmap from, sbitmap to);
 186 int longest_simple_path (ddg_ptr, int from, int to, sbitmap via);
 187
 188 bool autoinc_var_is_used_p (rtx, rtx);
 189
 190 #endif /* GCC_DDG_H */