gcc/timevar.h

   1 /* Timing variables for measuring compiler performance.
   2    Copyright (C) 2000-2020 Free Software Foundation, Inc.
   3    Contributed by Alex Samuel <samuel@codesourcery.com>
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    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 GCC_TIMEVAR_H
  22 #define GCC_TIMEVAR_H
  23
  24 /* Timing variables are used to measure elapsed time in various
  25    portions of the compiler.  Each measures elapsed user, system, and
  26    wall-clock time, as appropriate to and supported by the host
  27    system.
  28
  29    Timing variables are defined using the DEFTIMEVAR macro in
  30    timevar.def.  Each has an enumeral identifier, used when referring
  31    to the timing variable in code, and a character string name.
  32
  33    Timing variables can be used in two ways:
  34
  35      - On the timing stack, using timevar_push and timevar_pop.
  36        Timing variables may be pushed onto the stack; elapsed time is
  37        attributed to the topmost timing variable on the stack.  When
  38        another variable is pushed on, the previous topmost variable is
  39        `paused' until the pushed variable is popped back off.
  40
  41      - As a standalone timer, using timevar_start and timevar_stop.
  42        All time elapsed between the two calls is attributed to the
  43        variable.
  44 */
  45
  46 /* This structure stores the various varieties of time that can be
  47    measured.  Times are stored in seconds.  The time may be an
  48    absolute time or a time difference; in the former case, the time
  49    base is undefined, except that the difference between two times
  50    produces a valid time difference.  */
  51
  52 struct timevar_time_def
  53 {
  54   /* User time in this process.  */
  55   double user;
  56
  57   /* System time (if applicable for this host platform) in this
  58      process.  */
  59   double sys;
  60
  61   /* Wall clock time.  */
  62   double wall;
  63
  64   /* Garbage collector memory.  */
  65   size_t ggc_mem;
  66 };
  67
  68 /* An enumeration of timing variable identifiers.  Constructed from
  69    the contents of timevar.def.  */
  70
  71 #define DEFTIMEVAR(identifier__, name__) \
  72     identifier__,
  73 typedef enum
  74 {
  75   TV_NONE,
  76 #include "timevar.def"
  77   TIMEVAR_LAST
  78 }
  79 timevar_id_t;
  80 #undef DEFTIMEVAR
  81
  82 /* A class to hold all state relating to timing.  */
  83
  84 class timer;
  85
  86 /* The singleton instance of timing state.
  87
  88    This is non-NULL if timevars should be used.  In GCC, this happens with
  89    the -ftime-report flag.  Hence this is NULL for the common,
  90    needs-to-be-fast case, with an early reject happening for this being
  91    NULL.  */
  92 extern timer *g_timer;
  93
  94 /* Total amount of memory allocated by garbage collector.  */
  95 extern size_t timevar_ggc_mem_total;
  96
  97 extern void timevar_init (void);
  98 extern void timevar_start (timevar_id_t);
  99 extern void timevar_stop (timevar_id_t);
 100 extern bool timevar_cond_start (timevar_id_t);
 101 extern void timevar_cond_stop (timevar_id_t, bool);
 102
 103 /* The public (within GCC) interface for timing.  */
 104
 105 class timer
 106 {
 107  public:
 108   timer ();
 109   ~timer ();
 110
 111   void start (timevar_id_t tv);
 112   void stop (timevar_id_t tv);
 113   void push (timevar_id_t tv);
 114   void pop (timevar_id_t tv);
 115   bool cond_start (timevar_id_t tv);
 116   void cond_stop (timevar_id_t tv);
 117
 118   void push_client_item (const char *item_name);
 119   void pop_client_item ();
 120
 121   void print (FILE *fp);
 122
 123   const char *get_topmost_item_name () const;
 124
 125  private:
 126   /* Private member functions.  */
 127   void validate_phases (FILE *fp) const;
 128
 129   struct timevar_def;
 130   void push_internal (struct timevar_def *tv);
 131   void pop_internal ();
 132   static void print_row (FILE *fp,
 133                          const timevar_time_def *total,
 134                          const char *name, const timevar_time_def &elapsed);
 135   static bool all_zero (const timevar_time_def &elapsed);
 136
 137  private:
 138   typedef hash_map<timevar_def *, timevar_time_def> child_map_t;
 139
 140   /* Private type: a timing variable.  */
 141   struct timevar_def
 142   {
 143     /* Elapsed time for this variable.  */
 144     struct timevar_time_def elapsed;
 145
 146     /* If this variable is timed independently of the timing stack,
 147        using timevar_start, this contains the start time.  */
 148     struct timevar_time_def start_time;
 149
 150     /* The name of this timing variable.  */
 151     const char *name;
 152
 153     /* Nonzero if this timing variable is running as a standalone
 154        timer.  */
 155     unsigned standalone : 1;
 156
 157     /* Nonzero if this timing variable was ever started or pushed onto
 158        the timing stack.  */
 159     unsigned used : 1;
 160
 161     child_map_t *children;
 162   };
 163
 164   /* Private type: an element on the timing stack
 165      Elapsed time is attributed to the topmost timing variable on the
 166      stack.  */
 167   struct timevar_stack_def
 168   {
 169     /* The timing variable at this stack level.  */
 170     struct timevar_def *timevar;
 171
 172     /* The next lower timing variable context in the stack.  */
 173     struct timevar_stack_def *next;
 174   };
 175
 176   /* A class for managing a collection of named timing items, for use
 177      e.g. by libgccjit for timing client code.  This class is declared
 178      inside timevar.c to avoid everything using timevar.h
 179      from needing vec and hash_map.  */
 180   class named_items;
 181
 182  private:
 183
 184   /* Data members (all private).  */
 185
 186   /* Declared timing variables.  Constructed from the contents of
 187      timevar.def.  */
 188   timevar_def m_timevars[TIMEVAR_LAST];
 189
 190   /* The top of the timing stack.  */
 191   timevar_stack_def *m_stack;
 192
 193   /* A list of unused (i.e. allocated and subsequently popped)
 194      timevar_stack_def instances.  */
 195   timevar_stack_def *m_unused_stack_instances;
 196
 197   /* The time at which the topmost element on the timing stack was
 198      pushed.  Time elapsed since then is attributed to the topmost
 199      element.  */
 200   timevar_time_def m_start_time;
 201
 202   /* If non-NULL, for use when timing libgccjit's client code.  */
 203   named_items *m_jit_client_items;
 204
 205   friend class named_items;
 206 };
 207
 208 /* Provided for backward compatibility.  */
 209 static inline void
 210 timevar_push (timevar_id_t tv)
 211 {
 212   if (g_timer)
 213     g_timer->push (tv);
 214 }
 215
 216 static inline void
 217 timevar_pop (timevar_id_t tv)
 218 {
 219   if (g_timer)
 220     g_timer->pop (tv);
 221 }
 222
 223 // This is a simple timevar wrapper class that pushes a timevar in its
 224 // constructor and pops the timevar in its destructor.
 225 class auto_timevar
 226 {
 227  public:
 228   auto_timevar (timer *t, timevar_id_t tv)
 229     : m_timer (t),
 230       m_tv (tv)
 231   {
 232     if (m_timer)
 233       m_timer->push (m_tv);
 234   }
 235
 236   explicit auto_timevar (timevar_id_t tv)
 237     : m_timer (g_timer)
 238     , m_tv (tv)
 239   {
 240     if (m_timer)
 241       m_timer->push (m_tv);
 242   }
 243
 244   ~auto_timevar ()
 245   {
 246     if (m_timer)
 247       m_timer->pop (m_tv);
 248   }
 249
 250  private:
 251
 252   // Private to disallow copies.
 253   auto_timevar (const auto_timevar &);
 254
 255   timer *m_timer;
 256   timevar_id_t m_tv;
 257 };
 258
 259 extern void print_time (const char *, long);
 260
 261 #endif /* ! GCC_TIMEVAR_H */