gcc/ipa-struct-reorg.h

   1 /* Struct-reorg optimization.
   2    Copyright (C) 2002, 2003-2007, 2008, 2009 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 3 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; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef IPA_STRUCT_REORG_H
  22 #define IPA_STRUCT_REORG_H
  23
  24 /* This file contains data structures and interfaces required
  25    for struct-reorg optimizations.  */
  26
  27 /* An access site of the structure field.
  28    We consider an access to be of the following form:
  29
  30    D.2166_21 = i.6_20 * 8;
  31    D.2167_22 = (struct str_t *) D.2166_21;
  32    D.2168_24 = D.2167_22 + p.5_23;
  33    D.2169_25 = D.2168_24->b;
  34 */
  35
  36 struct field_access_site
  37 {
  38   /* Statement in which the access site occurs.  */
  39   gimple stmt;           /* D.2169_25 = D.2168_24->b;  */
  40   tree comp_ref;         /* D.2168_24->b  */
  41   tree field_decl;       /* b */
  42   tree ref;              /* D.2168_24  */
  43   tree num;              /* i.6_20  */
  44   tree offset;           /* D2167_22  */
  45   tree base;             /* p.5_23  */
  46   gimple ref_def_stmt;   /* D.2168_24 = D.2167_22 + p.5_23;  */
  47   gimple cast_stmt;      /* D.2167_22 = (struct str_t *) D.2166_21;
  48                             This statement is not always present.  */
  49 };
  50
  51 /* A non-field structure access site.  */
  52 struct access_site
  53 {
  54   /* A statement in which the access site occurs.  */
  55   gimple stmt;
  56   /* A list of structure variables in the access site.  */
  57   VEC (tree, heap) *vars;
  58 };
  59
  60 /* A field of the structure.  */
  61 struct field_entry
  62 {
  63   /* A field index.  */
  64   int index;
  65   /* Number of times the field is accessed (according to profiling).  */
  66   gcov_type count;
  67   tree decl;
  68   /* A type of a new structure this field belongs to.  */
  69   tree field_mapping;
  70   htab_t acc_sites;
  71 };
  72
  73 /* This structure represents a result of the structure peeling.
  74    The original structure is decomposed into substructures, or clusters.  */
  75 struct field_cluster
  76 {
  77   /* A bitmap of field indices. The set bit indicates that the field
  78      corresponding to it is a part of this cluster.  */
  79   sbitmap fields_in_cluster;
  80   struct field_cluster *sibling;
  81 };
  82
  83 /* An information about an individual structure type (RECORD_TYPE) required
  84    by struct-reorg optimizations to perform a transformation.  */
  85 struct data_structure
  86 {
  87
  88   /* A main variant of the structure type.  */
  89   tree decl;
  90
  91   /* Number of fields in the structure.  */
  92   int num_fields;
  93
  94   /* A structure access count collected through profiling.  */
  95   gcov_type count;
  96
  97   /* An array of the structure fields, indexed by field ID.  */
  98   struct field_entry *fields;
  99
 100   /* Non-field accesses of the structure.  */
 101   htab_t accs;
 102
 103   /* A data structure representing a reorganization decision.  */
 104   struct field_cluster *struct_clustering;
 105
 106   /* New types to replace the original structure type.  */
 107   VEC(tree, heap) *new_types;
 108 };
 109
 110 typedef struct data_structure * d_str;
 111
 112 #endif /* IPA_STRUCT_REORG_H */