gcc/optinfo.h

   1 /* Optimization information.
   2    Copyright (C) 2018 Free Software Foundation, Inc.
   3    Contributed by David Malcolm <dmalcolm@redhat.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_OPTINFO_H
  22 #define GCC_OPTINFO_H
  23
  24 /* An "optinfo" is a bundle of information describing part of an
  25    optimization, which can be emitted to zero or more of several
  26    destinations, such as:
  27
  28    * saved to a file as an "optimization record"
  29
  30    They are generated in response to calls to the "dump_*" API in
  31    dumpfile.h; repeated calls to the "dump_*" API are consolidated
  32    into a pending optinfo instance, with a "dump_*_loc" starting a new
  33    optinfo instance.
  34
  35    The data sent to the dump calls are captured within the pending optinfo
  36    instance as a sequence of optinfo_items.  For example, given:
  37
  38       if (dump_enabled_p ())
  39         {
  40           dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
  41                            "not vectorized: live stmt not supported: ");
  42           dump_gimple_stmt (MSG_MISSED_OPTIMIZATION, TDF_SLIM, stmt, 0);
  43         }
  44
  45    the "dump_printf_loc" call begins a new optinfo containing two items:
  46    (1) a text item containing "not vectorized: live stmt not supported: "
  47    (2) a gimple item for "stmt"
  48
  49    Dump destinations are thus able to access rich metadata about the
  50    items when the optinfo is emitted to them, rather than just having plain
  51    text.  For example, when saving the above optinfo to a file as an
  52    "optimization record", the record could capture the source location of
  53    "stmt" above, rather than just its textual form.
  54
  55    The currently pending optinfo is emitted and deleted:
  56    * each time a "dump_*_loc" call occurs (which starts the next optinfo), or
  57    * when the dump files are changed (at the end of a pass)
  58
  59    Dumping to an optinfo instance is non-trivial (due to building optinfo_item
  60    instances), so all usage should be guarded by
  61
  62      if (optinfo_enabled_p ())
  63
  64    which is off by default.  */
  65
  66
  67 /* Forward decls.  */
  68 struct opt_pass;
  69 class optinfo_item;
  70
  71 /* Should optinfo instances be created?
  72    All creation of optinfos should be guarded by this predicate.
  73    Return true if any optinfo destinations are active.  */
  74
  75 extern bool optinfo_enabled_p ();
  76
  77 /* Return true if any of the active optinfo destinations make use
  78    of inlining information.
  79    (if true, then the information is preserved).  */
  80
  81 extern bool optinfo_wants_inlining_info_p ();
  82
  83 /* The various kinds of optinfo.  */
  84
  85 enum optinfo_kind
  86 {
  87   OPTINFO_KIND_SUCCESS,
  88   OPTINFO_KIND_FAILURE,
  89   OPTINFO_KIND_NOTE,
  90   OPTINFO_KIND_SCOPE
  91 };
  92
  93 extern const char *optinfo_kind_to_string (enum optinfo_kind kind);
  94
  95 class dump_context;
  96
  97 /* A bundle of information describing part of an optimization.  */
  98
  99 class optinfo
 100 {
 101   friend class dump_context;
 102
 103  public:
 104   optinfo (const dump_location_t &loc,
 105            enum optinfo_kind kind,
 106            opt_pass *pass)
 107   : m_loc (loc), m_kind (kind), m_pass (pass), m_items ()
 108   {}
 109   ~optinfo ();
 110
 111   const dump_user_location_t &
 112   get_user_location () const { return m_loc.get_user_location (); }
 113
 114   const dump_impl_location_t &
 115   get_impl_location () const { return m_loc.get_impl_location (); }
 116
 117   enum optinfo_kind get_kind () const { return m_kind; }
 118   opt_pass *get_pass () const { return m_pass; }
 119   unsigned int num_items () const { return m_items.length (); }
 120   const optinfo_item *get_item (unsigned int i) const { return m_items[i]; }
 121
 122   location_t get_location_t () const { return m_loc.get_location_t (); }
 123   profile_count get_count () const { return m_loc.get_count (); }
 124
 125   void add_item (optinfo_item *item);
 126
 127  private:
 128   void emit ();
 129
 130   /* Pre-canned ways of manipulating the optinfo, for use by friend class
 131      dump_context.  */
 132   void handle_dump_file_kind (dump_flags_t);
 133
 134  private:
 135   dump_location_t m_loc;
 136   enum optinfo_kind m_kind;
 137   opt_pass *m_pass;
 138   auto_vec <optinfo_item *> m_items;
 139 };
 140
 141 /* An enum for discriminating between different kinds of optinfo_item.  */
 142
 143 enum optinfo_item_kind
 144 {
 145   OPTINFO_ITEM_KIND_TEXT,
 146   OPTINFO_ITEM_KIND_TREE,
 147   OPTINFO_ITEM_KIND_GIMPLE,
 148   OPTINFO_ITEM_KIND_SYMTAB_NODE
 149 };
 150
 151 /* An item within an optinfo.  */
 152
 153 class optinfo_item
 154 {
 155  public:
 156   optinfo_item (enum optinfo_item_kind kind, location_t location,
 157                 char *text);
 158   ~optinfo_item ();
 159
 160   enum optinfo_item_kind get_kind () const { return m_kind; }
 161   location_t get_location () const { return m_location; }
 162   const char *get_text () const { return m_text; }
 163
 164  private:
 165   /* Metadata (e.g. for optimization records).  */
 166   enum optinfo_item_kind m_kind;
 167   location_t m_location;
 168
 169   /* The textual form of the item, owned by the item.  */
 170   char *m_text;
 171 };
 172
 173 #endif /* #ifndef GCC_OPTINFO_H */