1  /* Routines required for instrumenting a program.  */
       2  /* Compile this one with gcc.  */
       3  /* Copyright (C) 1989-2023 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_topn
      37  void __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.  */
      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_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  
     102  void
     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 (-1);
     111        gcov_type n = gcov_get_counter_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 (-1);
     121  
     122  	  // TODO: we should use atomic here
     123  	  full |= gcov_topn_add_value (counters + GCOV_TOPN_MEM_COUNTERS * i,
     124  				       value, count, 0, 0);
     125  	}
     126  
     127        if (full)
     128  	*total = -(*total);
     129      }
     130  }
     131  #endif /* L_gcov_merge_topn */
     132  
     133  #endif /* inhibit_libc */