1 /* Routines required for instrumenting a program.  */
2 /* Compile this one with gcc.  */
3 /* Copyright (C) 1989-2018 Free Software Foundation, Inc.
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 
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
32 void __gcov_merge_add (gcov_type *counters  __attribute__ ((unused)),
33                        unsigned n_counters __attribute__ ((unused))) {}
34 #endif
35 
36 #ifdef L_gcov_merge_single
37 void __gcov_merge_single (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.  */
47 void
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.  */
59 void
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.  */
71 void
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_single
88 /* The profile merging function for choosing the most common value.
89    It is given an array COUNTERS of N_COUNTERS old counters and it
90    reads the same number of counters from the gcov file.  The counters
91    are split into 3-tuples where the members of the tuple have
92    meanings:
93 
94    -- the stored candidate on the most common value of the measured entity
95    -- counter
96    -- total number of evaluations of the value  */
97 void
98 __gcov_merge_single (gcov_type *counters, unsigned n_counters)
99 {
100   unsigned i, n_measures;
101   gcov_type value, counter, all;
102 
103   gcc_assert (!(n_counters % 3));
104   n_measures = n_counters / 3;
105   for (i = 0; i < n_measures; i++, counters += 3)
106     {
107       value = gcov_get_counter_target ();
108       counter = gcov_get_counter ();
109       all = gcov_get_counter ();
110 
111       if (counters[0] == value)
112         counters[1] += counter;
113       else if (counter > counters[1])
114         {
115           counters[0] = value;
116           counters[1] = counter - counters[1];
117         }
118       else
119         counters[1] -= counter;
120       counters[2] += all;
121     }
122 }
123 #endif /* L_gcov_merge_single */
124 
125 #ifdef L_gcov_merge_icall_topn
126 /* The profile merging function used for merging indirect call counts
127    This function is given array COUNTERS of N_COUNTERS old counters and it
128    reads the same number of counters from the gcov file.  */
129 
130 void
131 __gcov_merge_icall_topn (gcov_type *counters, unsigned n_counters)
132 {
133   unsigned i, j, k, m;
134 
135   gcc_assert (!(n_counters % GCOV_ICALL_TOPN_NCOUNTS));
136   for (i = 0; i < n_counters; i += GCOV_ICALL_TOPN_NCOUNTS)
137     {
138       gcov_type *value_array = &counters[i + 1];
139       unsigned tmp_size = 2 * (GCOV_ICALL_TOPN_NCOUNTS - 1);
140       gcov_type *tmp_array
141           = (gcov_type *) alloca (tmp_size * sizeof (gcov_type));
142 
143       for (j = 0; j < tmp_size; j++)
144         tmp_array[j] = 0;
145 
146       for (j = 0; j < GCOV_ICALL_TOPN_NCOUNTS - 1; j += 2)
147         {
148           tmp_array[j] = value_array[j];
149           tmp_array[j + 1] = value_array [j + 1];
150         }
151 
152       /* Skip the number_of_eviction entry.  */
153       gcov_get_counter ();
154       for (k = 0; k < GCOV_ICALL_TOPN_NCOUNTS - 1; k += 2)
155         {
156           int found = 0;
157           gcov_type global_id = gcov_get_counter_target ();
158           gcov_type call_count = gcov_get_counter ();
159           for (m = 0; m < j; m += 2)
160             {
161               if (tmp_array[m] == global_id)
162                 {
163                   found = 1;
164                   tmp_array[m + 1] += call_count;
165                   break;
166                 }
167             }
168           if (!found)
169             {
170               tmp_array[j] = global_id;
171               tmp_array[j + 1] = call_count;
172               j += 2;
173             }
174         }
175       /* Now sort the temp array */
176       gcov_sort_n_vals (tmp_array, j);
177 
178       /* Now copy back the top half of the temp array */
179       for (k = 0; k < GCOV_ICALL_TOPN_NCOUNTS - 1; k += 2)
180         {
181           value_array[k] = tmp_array[k];
182           value_array[k + 1] = tmp_array[k + 1];
183         }
184     }
185 }
186 #endif /* L_gcov_merge_icall_topn */
187 #endif /* inhibit_libc */
188