gcc/ipa-struct-reorg.h

   1 /* Struct-reorg optimization.
   2    Copyright (C) 2002, 2003-2007, 2008 Free Software Foundation, Inc.
   3    Contributed by Olga Golovanevsky <olga@il.ibm.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; if not, write to the Free Software
  19 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  21
  22 #ifndef IPA_STRUCT_REORG_H
  23 #define IPA_STRUCT_REORG_H
  24
  25 /* This file contains data structures and interfaces required
  26    for struct-reorg optimizations.  */
  27
  28 /* An access site of the structure field.
  29    We consider an access to be of the following form:
  30
  31    D.2166_21 = i.6_20 * 8;
  32    D.2167_22 = (struct str_t *) D.2166_21;
  33    D.2168_24 = D.2167_22 + p.5_23;
  34    D.2169_25 = D.2168_24->b;
  35 */
  36
  37 struct field_access_site
  38 {
  39   /* Statement in which the access site occurs.  */
  40   tree stmt;             /* D.2169_25 = D.2168_24->b;  */
  41   tree comp_ref;         /* D.2168_24->b  */
  42   tree field_decl;       /* b */
  43   tree ref;              /* D.2168_24  */
  44   tree num;              /* i.6_20  */
  45   tree offset;           /* D2167_22  */
  46   tree base;             /* p.5_23  */
  47   tree ref_def_stmt;     /* D.2168_24 = D.2167_22 + p.5_23;  */
  48   tree cast_stmt;        /* D.2167_22 = (struct str_t *) D.2166_21;
  49                             This statement is not always present.  */
  50 };
  51
  52 /* A non-field structure access site.  */
  53 struct access_site
  54 {
  55   /* A statement in which the access site occurs.  */
  56   tree stmt;
  57   /* A list of structure variables in the access site.  */
  58   VEC (tree, heap) *vars;
  59 };
  60
  61 /* A field of the structure.  */
  62 struct field_entry
  63 {
  64   /* A field index.  */
  65   int index;
  66   /* Number of times the field is accessed (according to profiling).  */
  67   gcov_type count;
  68   tree decl;
  69   /* A type of a new structure this field belongs to.  */
  70   tree field_mapping;
  71   htab_t acc_sites;
  72 };
  73
  74 /* This structure represents a result of the structure peeling.
  75    The original structure is decomposed into substructures, or clusters.  */
  76 struct field_cluster
  77 {
  78   /* A bitmap of field indices. The set bit indicates that the field
  79      corresponding to it is a part of this cluster.  */
  80   sbitmap fields_in_cluster;
  81   struct field_cluster *sibling;
  82 };
  83
  84 /* An information about an individual structure type (RECORD_TYPE) required
  85    by struct-reorg optimizations to perform a transformation.  */
  86 struct data_structure
  87 {
  88
  89   /* A main variant of the structure type.  */
  90   tree decl;
  91
  92   /* Number of fields in the structure.  */
  93   int num_fields;
  94
  95   /* A structure access count collected through profiling.  */
  96   gcov_type count;
  97
  98   /* An array of the structure fields, indexed by field ID.  */
  99   struct field_entry *fields;
 100
 101   /* Non-field accesses of the structure.  */
 102   htab_t accs;
 103
 104   /* A data structure representing a reorganization decision.  */
 105   struct field_cluster *struct_clustering;
 106
 107   /* New types to replace the original structure type.  */
 108   VEC(tree, heap) *new_types;
 109 };
 110
 111 typedef struct data_structure * d_str;
 112
 113 #endif /* IPA_STRUCT_REORG_H */