1 /* Timing variables for measuring compiler performance.
2 Copyright (C) 2000-2023 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.cc 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 inline void
210 timevar_push (timevar_id_t tv)
211 {
212 if (g_timer)
213 g_timer->push (tv);
214 }
215
216 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 // Disallow copies.
251 auto_timevar (const auto_timevar &) = delete;
252
253 private:
254 timer *m_timer;
255 timevar_id_t m_tv;
256 };
257
258 // As above, but use cond_start/stop.
259 class auto_cond_timevar
260 {
261 public:
262 auto_cond_timevar (timer *t, timevar_id_t tv)
263 : m_timer (t),
264 m_tv (tv)
265 {
266 start ();
267 }
268
269 explicit auto_cond_timevar (timevar_id_t tv)
270 : m_timer (g_timer)
271 , m_tv (tv)
272 {
273 start ();
274 }
275
276 ~auto_cond_timevar ()
277 {
278 if (m_timer && !already_running)
279 m_timer->cond_stop (m_tv);
280 }
281
282 // Disallow copies.
283 auto_cond_timevar (const auto_cond_timevar &) = delete;
284
285 private:
286 void start()
287 {
288 if (m_timer)
289 already_running = m_timer->cond_start (m_tv);
290 else
291 already_running = false;
292 }
293
294 timer *m_timer;
295 timevar_id_t m_tv;
296 bool already_running;
297 };
298
299 extern void print_time (const char *, long);
300
301 #endif /* ! GCC_TIMEVAR_H */