|
111
|
1 /* Routines required for instrumenting a program. */
|
|
|
2 /* Compile this one with gcc. */
|
|
145
|
3 /* Copyright (C) 1989-2020 Free Software Foundation, Inc.
|
|
111
|
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 Under Section 7 of GPL version 3, you are granted additional
|
|
|
18 permissions described in the GCC Runtime Library Exception, version
|
|
|
19 3.1, as published by the Free Software Foundation.
|
|
|
20
|
|
|
21 You should have received a copy of the GNU General Public License and
|
|
|
22 a copy of the GCC Runtime Library Exception along with this program;
|
|
|
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
|
24 <http://www.gnu.org/licenses/>. */
|
|
|
25
|
|
|
26 #include "libgcov.h"
|
|
|
27 #if !defined(inhibit_libc)
|
|
|
28
|
|
|
29 /* Detect whether target can support atomic update of profilers. */
|
|
|
30 #if __SIZEOF_LONG_LONG__ == 4 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
|
|
|
31 #define GCOV_SUPPORTS_ATOMIC 1
|
|
|
32 #else
|
|
|
33 #if __SIZEOF_LONG_LONG__ == 8 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
|
|
|
34 #define GCOV_SUPPORTS_ATOMIC 1
|
|
|
35 #else
|
|
|
36 #define GCOV_SUPPORTS_ATOMIC 0
|
|
|
37 #endif
|
|
|
38 #endif
|
|
|
39
|
|
|
40 #ifdef L_gcov_interval_profiler
|
|
|
41 /* If VALUE is in interval <START, START + STEPS - 1>, then increases the
|
|
|
42 corresponding counter in COUNTERS. If the VALUE is above or below
|
|
|
43 the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased
|
|
|
44 instead. */
|
|
|
45
|
|
|
46 void
|
|
|
47 __gcov_interval_profiler (gcov_type *counters, gcov_type value,
|
|
|
48 int start, unsigned steps)
|
|
|
49 {
|
|
|
50 gcov_type delta = value - start;
|
|
|
51 if (delta < 0)
|
|
|
52 counters[steps + 1]++;
|
|
|
53 else if (delta >= steps)
|
|
|
54 counters[steps]++;
|
|
|
55 else
|
|
|
56 counters[delta]++;
|
|
|
57 }
|
|
|
58 #endif
|
|
|
59
|
|
|
60 #if defined(L_gcov_interval_profiler_atomic) && GCOV_SUPPORTS_ATOMIC
|
|
|
61 /* If VALUE is in interval <START, START + STEPS - 1>, then increases the
|
|
|
62 corresponding counter in COUNTERS. If the VALUE is above or below
|
|
|
63 the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased
|
|
|
64 instead. Function is thread-safe. */
|
|
|
65
|
|
|
66 void
|
|
|
67 __gcov_interval_profiler_atomic (gcov_type *counters, gcov_type value,
|
|
|
68 int start, unsigned steps)
|
|
|
69 {
|
|
|
70 gcov_type delta = value - start;
|
|
|
71 if (delta < 0)
|
|
|
72 __atomic_fetch_add (&counters[steps + 1], 1, __ATOMIC_RELAXED);
|
|
|
73 else if (delta >= steps)
|
|
|
74 __atomic_fetch_add (&counters[steps], 1, __ATOMIC_RELAXED);
|
|
|
75 else
|
|
|
76 __atomic_fetch_add (&counters[delta], 1, __ATOMIC_RELAXED);
|
|
|
77 }
|
|
|
78 #endif
|
|
|
79
|
|
|
80 #ifdef L_gcov_pow2_profiler
|
|
|
81 /* If VALUE is a power of two, COUNTERS[1] is incremented. Otherwise
|
|
|
82 COUNTERS[0] is incremented. */
|
|
|
83
|
|
|
84 void
|
|
|
85 __gcov_pow2_profiler (gcov_type *counters, gcov_type value)
|
|
|
86 {
|
|
|
87 if (value == 0 || (value & (value - 1)))
|
|
|
88 counters[0]++;
|
|
|
89 else
|
|
|
90 counters[1]++;
|
|
|
91 }
|
|
|
92 #endif
|
|
|
93
|
|
|
94 #if defined(L_gcov_pow2_profiler_atomic) && GCOV_SUPPORTS_ATOMIC
|
|
|
95 /* If VALUE is a power of two, COUNTERS[1] is incremented. Otherwise
|
|
|
96 COUNTERS[0] is incremented. Function is thread-safe. */
|
|
|
97
|
|
|
98 void
|
|
|
99 __gcov_pow2_profiler_atomic (gcov_type *counters, gcov_type value)
|
|
|
100 {
|
|
|
101 if (value == 0 || (value & (value - 1)))
|
|
|
102 __atomic_fetch_add (&counters[0], 1, __ATOMIC_RELAXED);
|
|
|
103 else
|
|
|
104 __atomic_fetch_add (&counters[1], 1, __ATOMIC_RELAXED);
|
|
|
105 }
|
|
|
106 #endif
|
|
|
107
|
|
|
108
|
|
145
|
109 /* Tries to determine N most commons value among its inputs. */
|
|
111
|
110
|
|
|
111 static inline void
|
|
145
|
112 __gcov_topn_values_profiler_body (gcov_type *counters, gcov_type value,
|
|
|
113 int use_atomic)
|
|
111
|
114 {
|
|
145
|
115 if (use_atomic)
|
|
|
116 __atomic_fetch_add (&counters[0], 1, __ATOMIC_RELAXED);
|
|
|
117 else
|
|
|
118 counters[0]++;
|
|
|
119
|
|
|
120 ++counters;
|
|
|
121
|
|
|
122 /* First try to find an existing value. */
|
|
|
123 int empty_counter = -1;
|
|
|
124
|
|
|
125 for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
|
|
|
126 if (value == counters[2 * i])
|
|
|
127 {
|
|
|
128 if (use_atomic)
|
|
|
129 __atomic_fetch_add (&counters[2 * i + 1], GCOV_TOPN_VALUES,
|
|
|
130 __ATOMIC_RELAXED);
|
|
|
131 else
|
|
|
132 counters[2 * i + 1] += GCOV_TOPN_VALUES;
|
|
|
133 return;
|
|
|
134 }
|
|
|
135 else if (counters[2 * i + 1] <= 0)
|
|
|
136 empty_counter = i;
|
|
|
137
|
|
|
138 /* Find an empty slot for a new value. */
|
|
|
139 if (empty_counter != -1)
|
|
111
|
140 {
|
|
145
|
141 counters[2 * empty_counter] = value;
|
|
|
142 counters[2 * empty_counter + 1] = GCOV_TOPN_VALUES;
|
|
|
143 return;
|
|
111
|
144 }
|
|
|
145
|
|
145
|
146 /* We haven't found an empty slot, then decrement all
|
|
|
147 counter values by one. */
|
|
|
148 for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
|
|
|
149 if (use_atomic)
|
|
|
150 __atomic_fetch_sub (&counters[2 * i + 1], 1, __ATOMIC_RELAXED);
|
|
|
151 else
|
|
|
152 counters[2 * i + 1]--;
|
|
111
|
153 }
|
|
|
154
|
|
145
|
155 #ifdef L_gcov_topn_values_profiler
|
|
111
|
156 void
|
|
145
|
157 __gcov_topn_values_profiler (gcov_type *counters, gcov_type value)
|
|
111
|
158 {
|
|
145
|
159 __gcov_topn_values_profiler_body (counters, value, 0);
|
|
111
|
160 }
|
|
|
161 #endif
|
|
|
162
|
|
145
|
163 #if defined(L_gcov_topn_values_profiler_atomic) && GCOV_SUPPORTS_ATOMIC
|
|
111
|
164
|
|
|
165 /* Update one value profilers (COUNTERS) for a given VALUE.
|
|
|
166
|
|
|
167 CAVEAT: Following function is not thread-safe, only total number
|
|
|
168 of executions (COUNTERS[2]) is update with an atomic instruction.
|
|
|
169 Problem is that one cannot atomically update two counters
|
|
|
170 (COUNTERS[0] and COUNTERS[1]), for more information please read
|
|
|
171 following email thread:
|
|
|
172 https://gcc.gnu.org/ml/gcc-patches/2016-08/msg00024.html. */
|
|
|
173
|
|
|
174 void
|
|
145
|
175 __gcov_topn_values_profiler_atomic (gcov_type *counters, gcov_type value)
|
|
111
|
176 {
|
|
145
|
177 __gcov_topn_values_profiler_body (counters, value, 1);
|
|
111
|
178 }
|
|
|
179 #endif
|
|
|
180
|
|
145
|
181 #ifdef L_gcov_indirect_call_profiler_v4
|
|
111
|
182
|
|
|
183 /* These two variables are used to actually track caller and callee. Keep
|
|
|
184 them in TLS memory so races are not common (they are written to often).
|
|
|
185 The variables are set directly by GCC instrumented code, so declaration
|
|
|
186 here must match one in tree-profile.c */
|
|
|
187
|
|
|
188 #if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
|
|
|
189 __thread
|
|
|
190 #endif
|
|
131
|
191 struct indirect_call_tuple __gcov_indirect_call;
|
|
111
|
192
|
|
|
193 /* By default, the C++ compiler will use function addresses in the
|
|
|
194 vtable entries. Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
|
|
|
195 tells the compiler to use function descriptors instead. The value
|
|
|
196 of this macro says how many words wide the descriptor is (normally 2).
|
|
|
197
|
|
|
198 It is assumed that the address of a function descriptor may be treated
|
|
|
199 as a pointer to a function. */
|
|
|
200
|
|
|
201 /* Tries to determine the most common value among its inputs. */
|
|
145
|
202 static inline void
|
|
|
203 __gcov_indirect_call_profiler_body (gcov_type value, void *cur_func,
|
|
|
204 int use_atomic)
|
|
111
|
205 {
|
|
|
206 /* If the C++ virtual tables contain function descriptors then one
|
|
|
207 function may have multiple descriptors and we need to dereference
|
|
|
208 the descriptors to see if they point to the same function. */
|
|
131
|
209 if (cur_func == __gcov_indirect_call.callee
|
|
|
210 || (__LIBGCC_VTABLE_USES_DESCRIPTORS__
|
|
|
211 && *(void **) cur_func == *(void **) __gcov_indirect_call.callee))
|
|
145
|
212 __gcov_topn_values_profiler_body (__gcov_indirect_call.counters, value,
|
|
|
213 use_atomic);
|
|
111
|
214
|
|
131
|
215 __gcov_indirect_call.callee = NULL;
|
|
111
|
216 }
|
|
145
|
217
|
|
|
218 void
|
|
|
219 __gcov_indirect_call_profiler_v4 (gcov_type value, void *cur_func)
|
|
|
220 {
|
|
|
221 __gcov_indirect_call_profiler_body (value, cur_func, 0);
|
|
|
222 }
|
|
|
223
|
|
|
224 #if GCOV_SUPPORTS_ATOMIC
|
|
|
225 void
|
|
|
226 __gcov_indirect_call_profiler_v4_atomic (gcov_type value, void *cur_func)
|
|
|
227 {
|
|
|
228 __gcov_indirect_call_profiler_body (value, cur_func, 1);
|
|
|
229 }
|
|
|
230 #endif
|
|
|
231
|
|
111
|
232 #endif
|
|
|
233
|
|
|
234 #ifdef L_gcov_time_profiler
|
|
|
235
|
|
|
236 /* Counter for first visit of each function. */
|
|
145
|
237 gcov_type __gcov_time_profiler_counter ATTRIBUTE_HIDDEN;
|
|
111
|
238
|
|
|
239 #endif
|
|
|
240
|
|
|
241 #ifdef L_gcov_average_profiler
|
|
|
242 /* Increase corresponding COUNTER by VALUE. FIXME: Perhaps we want
|
|
|
243 to saturate up. */
|
|
|
244
|
|
|
245 void
|
|
|
246 __gcov_average_profiler (gcov_type *counters, gcov_type value)
|
|
|
247 {
|
|
|
248 counters[0] += value;
|
|
|
249 counters[1] ++;
|
|
|
250 }
|
|
|
251 #endif
|
|
|
252
|
|
|
253 #if defined(L_gcov_average_profiler_atomic) && GCOV_SUPPORTS_ATOMIC
|
|
|
254 /* Increase corresponding COUNTER by VALUE. FIXME: Perhaps we want
|
|
|
255 to saturate up. Function is thread-safe. */
|
|
|
256
|
|
|
257 void
|
|
|
258 __gcov_average_profiler_atomic (gcov_type *counters, gcov_type value)
|
|
|
259 {
|
|
|
260 __atomic_fetch_add (&counters[0], value, __ATOMIC_RELAXED);
|
|
|
261 __atomic_fetch_add (&counters[1], 1, __ATOMIC_RELAXED);
|
|
|
262 }
|
|
|
263 #endif
|
|
|
264
|
|
|
265 #ifdef L_gcov_ior_profiler
|
|
|
266 /* Bitwise-OR VALUE into COUNTER. */
|
|
|
267
|
|
|
268 void
|
|
|
269 __gcov_ior_profiler (gcov_type *counters, gcov_type value)
|
|
|
270 {
|
|
|
271 *counters |= value;
|
|
|
272 }
|
|
|
273 #endif
|
|
|
274
|
|
|
275 #if defined(L_gcov_ior_profiler_atomic) && GCOV_SUPPORTS_ATOMIC
|
|
|
276 /* Bitwise-OR VALUE into COUNTER. Function is thread-safe. */
|
|
|
277
|
|
|
278 void
|
|
|
279 __gcov_ior_profiler_atomic (gcov_type *counters, gcov_type value)
|
|
|
280 {
|
|
|
281 __atomic_fetch_or (&counters[0], value, __ATOMIC_RELAXED);
|
|
|
282 }
|
|
|
283 #endif
|
|
|
284
|
|
|
285
|
|
|
286 #endif /* inhibit_libc */
|
