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gcc/libgcc/libgcov-merge.c
Jan Hubicka e3fe0070c1 libgcov: Fix merging of topn [PR92924]
PR tree-optimization/92924
	* libgcov-merge.c (merge_topn_values_set): Fix merging.
2020-01-24 12:12:17 +01:00

169 lines
4.8 KiB
C

/* Routines required for instrumenting a program. */
/* Compile this one with gcc. */
/* Copyright (C) 1989-2020 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "libgcov.h"
#if defined(inhibit_libc)
/* If libc and its header files are not available, provide dummy functions. */
#ifdef L_gcov_merge_add
void __gcov_merge_add (gcov_type *counters __attribute__ ((unused)),
unsigned n_counters __attribute__ ((unused))) {}
#endif
#ifdef L_gcov_merge_topn
void __gcov_merge_topn (gcov_type *counters __attribute__ ((unused)),
unsigned n_counters __attribute__ ((unused))) {}
#endif
#else
#ifdef L_gcov_merge_add
/* The profile merging function that just adds the counters. It is given
an array COUNTERS of N_COUNTERS old counters and it reads the same number
of counters from the gcov file. */
void
__gcov_merge_add (gcov_type *counters, unsigned n_counters)
{
for (; n_counters; counters++, n_counters--)
*counters += gcov_get_counter ();
}
#endif /* L_gcov_merge_add */
#ifdef L_gcov_merge_ior
/* The profile merging function that just adds the counters. It is given
an array COUNTERS of N_COUNTERS old counters and it reads the same number
of counters from the gcov file. */
void
__gcov_merge_ior (gcov_type *counters, unsigned n_counters)
{
for (; n_counters; counters++, n_counters--)
*counters |= gcov_get_counter_target ();
}
#endif
#ifdef L_gcov_merge_time_profile
/* Time profiles are merged so that minimum from all valid (greater than zero)
is stored. There could be a fork that creates new counters. To have
the profile stable, we chosen to pick the smallest function visit time. */
void
__gcov_merge_time_profile (gcov_type *counters, unsigned n_counters)
{
unsigned int i;
gcov_type value;
for (i = 0; i < n_counters; i++)
{
value = gcov_get_counter_target ();
if (value && (!counters[i] || value < counters[i]))
counters[i] = value;
}
}
#endif /* L_gcov_merge_time_profile */
#ifdef L_gcov_merge_topn
static void
merge_topn_values_set (gcov_type *counters)
{
/* First value is number of total executions of the profiler. */
gcov_type all = gcov_get_counter_ignore_scaling (-1);
counters[0] += all;
++counters;
/* Read all part values. */
gcov_type read_counters[2 * GCOV_TOPN_VALUES];
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
{
read_counters[2 * i] = gcov_get_counter_target ();
read_counters[2 * i + 1] = gcov_get_counter_ignore_scaling (-1);
}
if (read_counters[1] == -1)
{
counters[1] = -1;
return;
}
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
{
if (read_counters[2 * i + 1] == 0)
continue;
unsigned j;
int slot = -1;
for (j = 0; j < GCOV_TOPN_VALUES; j++)
{
if (counters[2 * j] == read_counters[2 * i])
{
counters[2 * j + 1] += read_counters[2 * i + 1];
break;
}
else if (counters[2 * j + 1] == 0)
slot = j;
}
if (j == GCOV_TOPN_VALUES)
{
if (slot > 0)
{
/* If we found empty slot, add the value. */
counters[2 * slot] = read_counters[2 * i];
counters[2 * slot + 1] = read_counters[2 * i + 1];
}
else
{
/* We haven't found a slot, bail out. */
counters[1] = -1;
return;
}
}
}
}
/* The profile merging function for choosing the most common value.
It is given an array COUNTERS of N_COUNTERS old counters and it
reads the same number of counters from the gcov file. The counters
are split into pairs where the members of the tuple have
meanings:
-- the stored candidate on the most common value of the measured entity
-- counter
*/
void
__gcov_merge_topn (gcov_type *counters, unsigned n_counters)
{
gcc_assert (!(n_counters % GCOV_TOPN_VALUES_COUNTERS));
for (unsigned i = 0; i < (n_counters / GCOV_TOPN_VALUES_COUNTERS); i++)
merge_topn_values_set (counters + (i * GCOV_TOPN_VALUES_COUNTERS));
}
#endif /* L_gcov_merge_topn */
#endif /* inhibit_libc */