1/* Routines required for instrumenting a program. */
2/* Compile this one with gcc. */
3/* Copyright (C) 1989-2023 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
16
17Under Section 7 of GPL version 3, you are granted additional
18permissions described in the GCC Runtime Library Exception, version
193.1, as published by the Free Software Foundation.
20
21You should have received a copy of the GNU General Public License and
22a copy of the GCC Runtime Library Exception along with this program;
23see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24<http://www.gnu.org/licenses/>. */
25
26#include "libgcov.h"
27
28#if defined(inhibit_libc)
29/* If libc and its header files are not available, provide dummy functions. */
30
31#ifdef L_gcov_merge_add
32void __gcov_merge_add (gcov_type *counters __attribute__ ((unused)),
33 unsigned n_counters __attribute__ ((unused))) {}
34#endif
35
36#ifdef L_gcov_merge_topn
37void __gcov_merge_topn (gcov_type *counters __attribute__ ((unused)),
38 unsigned n_counters __attribute__ ((unused))) {}
39#endif
40
41#else
42
43#ifdef L_gcov_merge_add
44/* The profile merging function that just adds the counters. It is given
45 an array COUNTERS of N_COUNTERS old counters and it reads the same number
46 of counters from the gcov file. */
47void
48__gcov_merge_add (gcov_type *counters, unsigned n_counters)
49{
50 for (; n_counters; counters++, n_counters--)
51 *counters += gcov_get_counter ();
52}
53#endif /* L_gcov_merge_add */
54
55#ifdef L_gcov_merge_ior
56/* The profile merging function that just adds the counters. It is given
57 an array COUNTERS of N_COUNTERS old counters and it reads the same number
58 of counters from the gcov file. */
59void
60__gcov_merge_ior (gcov_type *counters, unsigned n_counters)
61{
62 for (; n_counters; counters++, n_counters--)
63 *counters |= gcov_get_counter_target ();
64}
65#endif
66
67#ifdef L_gcov_merge_time_profile
68/* Time profiles are merged so that minimum from all valid (greater than zero)
69 is stored. There could be a fork that creates new counters. To have
70 the profile stable, we chosen to pick the smallest function visit time. */
71void
72__gcov_merge_time_profile (gcov_type *counters, unsigned n_counters)
73{
74 unsigned int i;
75 gcov_type value;
76
77 for (i = 0; i < n_counters; i++)
78 {
79 value = gcov_get_counter_target ();
80
81 if (value && (!counters[i] || value < counters[i]))
82 counters[i] = value;
83 }
84}
85#endif /* L_gcov_merge_time_profile */
86
87#ifdef L_gcov_merge_topn
88
89/* The profile merging function for choosing the most common value.
90 It is given an array COUNTERS of N_COUNTERS old counters and it
91 reads the same number of counters from the gcov file. The counters
92 are split into pairs where the members of the tuple have
93 meanings:
94
95 -- the stored candidate on the most common value of the measured entity
96 -- counter
97
98 We use -TOTAL for situation when merging dropped some values.
99 The information is used for -fprofile-reproducible flag.
100 */
101
102void
103__gcov_merge_topn (gcov_type *counters, unsigned n_counters)
104{
105 gcc_assert (!(n_counters % GCOV_TOPN_MEM_COUNTERS));
106
107 for (unsigned i = 0; i < (n_counters / GCOV_TOPN_MEM_COUNTERS); i++)
108 {
109 /* First value is number of total executions of the profiler. */
110 gcov_type all = gcov_get_counter_ignore_scaling (ignore_scaling: -1);
111 gcov_type n = gcov_get_counter_ignore_scaling (ignore_scaling: -1);
112
113 unsigned full = all < 0;
114 gcov_type *total = &counters[GCOV_TOPN_MEM_COUNTERS * i];
115 *total += full ? -all : all;
116
117 for (unsigned j = 0; j < n; j++)
118 {
119 gcov_type value = gcov_get_counter_target ();
120 gcov_type count = gcov_get_counter_ignore_scaling (ignore_scaling: -1);
121
122 // TODO: we should use atomic here
123 full |= gcov_topn_add_value (counters: counters + GCOV_TOPN_MEM_COUNTERS * i,
124 value, count, use_atomic: 0, increment_total: 0);
125 }
126
127 if (full)
128 *total = -(*total);
129 }
130}
131#endif /* L_gcov_merge_topn */
132
133#endif /* inhibit_libc */
134

source code of libgcc/libgcov-merge.c