FreeChainXenon/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Make TOPN counter dynamically allocated.

Browse source 
gcc/ChangeLog:

	* coverage.c (get_coverage_counts): Skip sanity check for TOP N counters
	as they have variable number of counters.
	* gcov-dump.c (main): Add new option -r.
	(print_usage): Likewise.
	(tag_counters): All new raw format.
	* gcov-io.h (struct gcov_kvp): New.
	(GCOV_TOPN_VALUES): Remove.
	(GCOV_TOPN_VALUES_COUNTERS): Likewise.
	(GCOV_TOPN_MEM_COUNTERS): New.
	(GCOV_TOPN_DISK_COUNTERS): Likewise.
	(GCOV_TOPN_MAXIMUM_TRACKED_VALUES): Likewise.
	* ipa-profile.c (ipa_profile_generate_summary): Use
	GCOV_TOPN_MAXIMUM_TRACKED_VALUES.
	(ipa_profile_write_edge_summary): Likewise.
	(ipa_profile_read_edge_summary): Likewise.
	(ipa_profile): Remove usage of GCOV_TOPN_VALUES.
	* profile.c (sort_hist_values): Sort variable number
	of counters.
	(compute_value_histograms): Special case for TOP N counters
	that have dynamic number of key-value pairs.
	* value-prof.c (dump_histogram_value): Dump variable number
	of key-value pairs.
	(stream_in_histogram_value): Stream in variable number
	of key-value pairs for TOP N counter.
	(get_nth_most_common_value): Deal with variable number
	of key-value pairs.
	(dump_ic_profile): Use GCOV_TOPN_MAXIMUM_TRACKED_VALUES
	for loop iteration.
	(gimple_find_values_to_profile): Set GCOV_TOPN_MEM_COUNTERS
	to n_counters.
	* doc/gcov-dump.texi: Document new -r option.

libgcc/ChangeLog:

	* libgcov-driver.c (prune_topn_counter): Remove.
	(prune_counters): Likewise.
	(merge_one_data): Special case TOP N counters
	as they have variable length.
	(write_top_counters): New.
	(write_one_data): Special case TOP N.
	(dump_one_gcov): Do not prune TOP N counters.
	* libgcov-merge.c (merge_topn_values_set): Remove.
	(__gcov_merge_topn): Use gcov_topn_add_value.
	* libgcov-profiler.c (__gcov_topn_values_profiler_body):
	Likewise here.
	* libgcov.h (gcov_counter_add): New.
	(gcov_counter_set_if_null): Likewise.
	(gcov_topn_add_value): New.
This commit is contained in:
Martin Liska 2020-01-31 13:10:14 +01:00
parent 23438370f7
commit 871e5ada6d
No known key found for this signature in database
GPG key ID: 4DC182DC0FA73785
11 changed files with 285 additions and 249 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
gcc/coverage.c
View file

@ -345,8 +345,11 @@ get_coverage_counts (unsigned counter, unsigned cfg_checksum,
can do about it. */
return NULL;
}
if (entry->cfg_checksum != cfg_checksum || entry->n_counts != n_counts)
if (entry->cfg_checksum != cfg_checksum
|| (counter != GCOV_COUNTER_V_INDIR
&& counter != GCOV_COUNTER_V_TOPN
&& entry->n_counts != n_counts))
{
static int warned = 0;
bool warning_printed = false;

5
gcc/doc/gcov-dump.texi
View file

@ -61,6 +61,7 @@ gcov-dump [@option{-v}|@option{--version}]
[@option{-h}|@option{--help}]
[@option{-l}|@option{--long}]
[@option{-p}|@option{--positions}]
[@option{-r}|@option{--raw}]
@var{gcovfiles}
@c man end
@end ignore
@ -80,6 +81,10 @@ Dump content of records.
@itemx --positions
Dump positions of records.
@item -r
@itemx --raw
Print content records in raw format.
@item -v
@itemx --version
Display the @command{gcov-dump} version number (on the standard output),

14
gcc/gcov-dump.c
View file

@ -49,6 +49,7 @@ typedef struct tag_format
static int flag_dump_contents = 0;
static int flag_dump_positions = 0;
static int flag_dump_raw = 0;
static const struct option options[] =
{
@ -95,7 +96,7 @@ main (int argc ATTRIBUTE_UNUSED, char **argv)
diagnostic_initialize (global_dc, 0);
while ((opt = getopt_long (argc, argv, "hlpvw", options, NULL)) != -1)
while ((opt = getopt_long (argc, argv, "hlprvw", options, NULL)) != -1)
{
switch (opt)
{
@ -111,6 +112,9 @@ main (int argc ATTRIBUTE_UNUSED, char **argv)
case 'p':
flag_dump_positions = 1;
break;
case 'r':
flag_dump_raw = 1;
break;
default:
fprintf (stderr, "unknown flag `%c'\n", opt);
}
@ -129,6 +133,7 @@ print_usage (void)
printf (" -h, --help Print this help\n");
printf (" -l, --long Dump record contents too\n");
printf (" -p, --positions Dump record positions\n");
printf (" -r, --raw Print content records in raw format\n");
printf (" -v, --version Print version number\n");
printf ("\nFor bug reporting instructions, please see:\n%s.\n",
bug_report_url);
@ -441,7 +446,12 @@ tag_counters (const char *filename ATTRIBUTE_UNUSED,
{
gcov_type count;
if (!(ix & 7))
if (flag_dump_raw)
{
if (ix == 0)
printf (": ");
}
else if (!(ix & 7))
{
printf ("\n");
print_prefix (filename, depth, gcov_position ());

22
gcc/gcov-io.h
View file

@ -170,6 +170,17 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
#ifndef GCC_GCOV_IO_H
#define GCC_GCOV_IO_H
/* GCOV key-value pair linked list type. */
struct gcov_kvp;
struct gcov_kvp
{
gcov_type value;
gcov_type count;
struct gcov_kvp *next;
};
#ifndef IN_LIBGCOV
/* About the host */
@ -272,11 +283,14 @@ GCOV_COUNTERS
#define GCOV_N_VALUE_COUNTERS \
(GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
/* Number of top N value histogram. */
#define GCOV_TOPN_VALUES 4
/* Number of top N counters when being in memory. */
#define GCOV_TOPN_MEM_COUNTERS 3
/* Total number of single value counters. */
#define GCOV_TOPN_VALUES_COUNTERS (2 * GCOV_TOPN_VALUES + 1)
/* Number of top N counters in disk representation. */
#define GCOV_TOPN_DISK_COUNTERS 2
/* Maximum number of tracked TOP N value profiles. */
#define GCOV_TOPN_MAXIMUM_TRACKED_VALUES 32
/* Convert a counter index to a tag. */
#define GCOV_TAG_FOR_COUNTER(COUNT) \

11
gcc/ipa-profile.c
View file

@ -295,7 +295,8 @@ ipa_profile_generate_summary (void)
speculative_call_summary *csum
= call_sums->get_create (e);
for (unsigned j = 0; j < GCOV_TOPN_VALUES; j++)
for (unsigned j = 0; j < GCOV_TOPN_MAXIMUM_TRACKED_VALUES;
j++)
{
if (!get_nth_most_common_value (NULL, "indirect call",
h, &val, &count, &all,
@ -342,7 +343,7 @@ ipa_profile_write_edge_summary (lto_simple_output_block *ob,
len = csum->speculative_call_targets.length ();
gcc_assert (len <= GCOV_TOPN_VALUES);
gcc_assert (len <= GCOV_TOPN_MAXIMUM_TRACKED_VALUES);
streamer_write_hwi_stream (ob->main_stream, len);
@ -448,8 +449,7 @@ ipa_profile_read_edge_summary (class lto_input_block *ib, cgraph_edge *edge)
unsigned i, len;
len = streamer_read_hwi (ib);
gcc_assert (len <= GCOV_TOPN_VALUES);
gcc_assert (len <= GCOV_TOPN_MAXIMUM_TRACKED_VALUES);
speculative_call_summary *csum = call_sums->get_create (edge);
for (i = 0; i < len; i++)
@ -885,8 +885,7 @@ ipa_profile (void)
item.target_probability
/ (float) REG_BR_PROB_BASE);
}
if (item.target_probability
< REG_BR_PROB_BASE / GCOV_TOPN_VALUES / 2)
if (item.target_probability < REG_BR_PROB_BASE / 2)
{
nuseless++;
if (dump_file)

70
gcc/profile.c
View file

@ -765,26 +765,22 @@ compute_branch_probabilities (unsigned cfg_checksum, unsigned lineno_checksum)
static void
sort_hist_values (histogram_value hist)
{
/* counters[2] equal to -1 means that all counters are invalidated. */
if (hist->hvalue.counters[2] == -1)
return;
gcc_assert (hist->type == HIST_TYPE_TOPN_VALUES
|| hist->type == HIST_TYPE_INDIR_CALL);
gcc_assert (hist->n_counters == GCOV_TOPN_VALUES_COUNTERS);
int counters = hist->hvalue.counters[1];
for (int i = 0; i < counters - 1; i++)
/* Hist value is organized as:
[total_executions, value1, counter1, ..., value4, counter4]
[total_executions, N, counter1, ..., valueN, counterN]
Use decrease bubble sort to rearrange it. The sort starts from <value1,
counter1> and compares counter first. If counter is same, compares the
value, exchange it if small to keep stable. */
for (unsigned i = 0; i < GCOV_TOPN_VALUES - 1; i++)
{
bool swapped = false;
for (unsigned j = 0; j < GCOV_TOPN_VALUES - 1 - i; j++)
for (int j = 0; j < counters - 1 - i; j++)
{
gcov_type *p = &hist->hvalue.counters[2 * j + 1];
gcov_type *p = &hist->hvalue.counters[2 * j + 2];
if (p[1] < p[3] || (p[1] == p[3] && p[0] < p[2]))
{
std::swap (p[0], p[2]);
@ -847,31 +843,43 @@ compute_value_histograms (histogram_values values, unsigned cfg_checksum,
gimple *stmt = hist->hvalue.stmt;
t = (int) hist->type;
bool topn_p = (hist->type == HIST_TYPE_TOPN_VALUES
|| hist->type == HIST_TYPE_INDIR_CALL);
aact_count = act_count[t];
if (act_count[t])
act_count[t] += hist->n_counters;
gimple_add_histogram_value (cfun, stmt, hist);
hist->hvalue.counters = XNEWVEC (gcov_type, hist->n_counters);
for (j = 0; j < hist->n_counters; j++)
if (aact_count)
hist->hvalue.counters[j] = aact_count[j];
else
hist->hvalue.counters[j] = 0;
if (hist->type == HIST_TYPE_TOPN_VALUES
|| hist->type == HIST_TYPE_INDIR_CALL)
/* TOP N counter uses variable number of counters. */
if (topn_p)
{
/* Each count value is multiplied by GCOV_TOPN_VALUES. */
if (hist->hvalue.counters[2] != -1)
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
hist->hvalue.counters[2 * i + 2]
= RDIV (hist->hvalue.counters[2 * i + 2], GCOV_TOPN_VALUES);
unsigned total_size;
if (act_count[t])
total_size = 2 + 2 * act_count[t][1];
else
total_size = 2;
gimple_add_histogram_value (cfun, stmt, hist);
hist->n_counters = total_size;
hist->hvalue.counters = XNEWVEC (gcov_type, hist->n_counters);
for (j = 0; j < hist->n_counters; j++)
if (act_count[t])
hist->hvalue.counters[j] = act_count[t][j];
else
hist->hvalue.counters[j] = 0;
act_count[t] += hist->n_counters;
sort_hist_values (hist);
}
else
{
aact_count = act_count[t];
if (act_count[t])
act_count[t] += hist->n_counters;
gimple_add_histogram_value (cfun, stmt, hist);
hist->hvalue.counters = XNEWVEC (gcov_type, hist->n_counters);
for (j = 0; j < hist->n_counters; j++)
if (aact_count)
hist->hvalue.counters[j] = aact_count[j];
else
hist->hvalue.counters[j] = 0;
}
/* Time profiler counter is not related to any statement,
so that we have to read the counter and set the value to

59
gcc/value-prof.c
View file

@ -265,16 +265,15 @@ dump_histogram_value (FILE *dump_file, histogram_value hist)
? "Top N value counter" : "Indirect call counter"));
if (hist->hvalue.counters)
{
fprintf (dump_file, " all: %" PRId64 "%s, values: ",
(int64_t) abs_hwi (hist->hvalue.counters[0]),
hist->hvalue.counters[0] < 0
? " (values missing)": "");
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
unsigned count = hist->hvalue.counters[1];
fprintf (dump_file, " all: %" PRId64 ", %" PRId64 " values: ",
(int64_t) hist->hvalue.counters[0], (int64_t) count);
for (unsigned i = 0; i < count; i++)
{
fprintf (dump_file, "[%" PRId64 ":%" PRId64 "]",
(int64_t) hist->hvalue.counters[2 * i + 1],
(int64_t) hist->hvalue.counters[2 * i + 2]);
if (i != GCOV_TOPN_VALUES - 1)
(int64_t) hist->hvalue.counters[2 * i + 2],
(int64_t) hist->hvalue.counters[2 * i + 3]);
if (i != count - 1)
fprintf (dump_file, ", ");
}
fprintf (dump_file, ".\n");
@ -377,7 +376,6 @@ stream_in_histogram_value (class lto_input_block *ib, gimple *stmt)
case HIST_TYPE_TOPN_VALUES:
case HIST_TYPE_INDIR_CALL:
ncounters = GCOV_TOPN_VALUES_COUNTERS;
break;
case HIST_TYPE_IOR:
@ -388,12 +386,31 @@ stream_in_histogram_value (class lto_input_block *ib, gimple *stmt)
default:
gcc_unreachable ();
}
new_val->hvalue.counters = XNEWVAR (gcov_type,
sizeof (*new_val->hvalue.counters)
* ncounters);
new_val->n_counters = ncounters;
for (i = 0; i < ncounters; i++)
new_val->hvalue.counters[i] = streamer_read_gcov_count (ib);
/* TOP N counters have variable number of counters. */
if (type == HIST_TYPE_INDIR_CALL || type == HIST_TYPE_TOPN_VALUES)
{
gcov_type total = streamer_read_gcov_count (ib);
gcov_type ncounters = streamer_read_gcov_count (ib);
new_val->hvalue.counters = XNEWVAR (gcov_type,
sizeof (*new_val->hvalue.counters)
* (2 + 2 * ncounters));
new_val->hvalue.counters[0] = total;
new_val->hvalue.counters[1] = ncounters;
new_val->n_counters = 2 + 2 * ncounters;
for (i = 0; i < 2 * ncounters; i++)
new_val->hvalue.counters[2 + i] = streamer_read_gcov_count (ib);
}
else
{
new_val->hvalue.counters = XNEWVAR (gcov_type,
sizeof (*new_val->hvalue.counters)
* ncounters);
new_val->n_counters = ncounters;
for (i = 0; i < ncounters; i++)
new_val->hvalue.counters[i] = streamer_read_gcov_count (ib);
}
if (!next_p)
gimple_add_histogram_value (cfun, stmt, new_val);
else
@ -738,15 +755,17 @@ get_nth_most_common_value (gimple *stmt, const char *counter_type,
histogram_value hist, gcov_type *value,
gcov_type *count, gcov_type *all, unsigned n)
{
gcc_assert (n < GCOV_TOPN_VALUES);
unsigned counters = hist->hvalue.counters[1];
if (n >= counters)
return false;
*count = 0;
*value = 0;
gcov_type read_all = abs_hwi (hist->hvalue.counters[0]);
gcov_type v = hist->hvalue.counters[2 * n + 1];
gcov_type c = hist->hvalue.counters[2 * n + 2];
gcov_type v = hist->hvalue.counters[2 * n + 2];
gcov_type c = hist->hvalue.counters[2 * n + 3];
if (hist->hvalue.counters[0] < 0
&& (flag_profile_reproducible == PROFILE_REPRODUCIBILITY_PARALLEL_RUNS
@ -1433,7 +1452,7 @@ dump_ic_profile (gimple_stmt_iterator *gsi)
count = 0;
all = histogram->hvalue.counters[0];
for (unsigned j = 0; j < GCOV_TOPN_VALUES; j++)
for (unsigned j = 0; j < GCOV_TOPN_MAXIMUM_TRACKED_VALUES; j++)
{
if (!get_nth_most_common_value (NULL, "indirect call", histogram, &val,
&count, &all, j))
@ -1902,7 +1921,7 @@ gimple_find_values_to_profile (histogram_values *values)
case HIST_TYPE_TOPN_VALUES:
case HIST_TYPE_INDIR_CALL:
hist->n_counters = GCOV_TOPN_VALUES_COUNTERS;
hist->n_counters = GCOV_TOPN_MEM_COUNTERS;
break;
case HIST_TYPE_TIME_PROFILE:

116
libgcc/libgcov-driver.c
View file

@ -213,51 +213,6 @@ static struct gcov_fn_buffer *fn_buffer;
/* Including system dependent components. */
#include "libgcov-driver-system.c"
/* Prune TOP N value COUNTERS. It's needed in order to preserve
reproducibility of builds. */
static void
prune_topn_counter (gcov_type *counters, gcov_type all)
{
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
if (counters[2 * i + 1] < all)
{
counters[2 * i] = 0;
counters[2 * i + 1] = 0;
}
}
/* Prune counters so that they are ready to store or merge. */
static void
prune_counters (struct gcov_info *gi)
{
for (unsigned i = 0; i < gi->n_functions; i++)
{
const struct gcov_fn_info *gfi = gi->functions[i];
const struct gcov_ctr_info *ci = gfi->ctrs;
for (unsigned j = 0; j < GCOV_COUNTERS; j++)
{
if (gi->merge[j] == NULL)
continue;
if (gi->merge[j] == __gcov_merge_topn)
{
gcc_assert (!(ci->num % GCOV_TOPN_VALUES_COUNTERS));
for (unsigned k = 0; k < (ci->num / GCOV_TOPN_VALUES_COUNTERS);
k++)
{
gcov_type *counters
= ci->values + (k * GCOV_TOPN_VALUES_COUNTERS);
prune_topn_counter (counters + 1, *counters);
}
}
ci++;
}
}
}
/* This function merges counters in GI_PTR to an existing gcda file.
Return 0 on success.
Return -1 on error. In this case, caller will goto read_fatal. */
@ -346,16 +301,18 @@ merge_one_data (const char *filename,
if (!merge)
continue;
tag = gcov_read_unsigned ();
length = gcov_read_unsigned ();
if (tag != GCOV_TAG_FOR_COUNTER (t_ix)
|| length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num))
goto read_mismatch;
(*merge) (ci_ptr->values, ci_ptr->num);
ci_ptr++;
}
tag = gcov_read_unsigned ();
length = gcov_read_unsigned ();
if (tag != GCOV_TAG_FOR_COUNTER (t_ix)
|| (length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num)
&& t_ix != GCOV_COUNTER_V_TOPN
&& t_ix != GCOV_COUNTER_V_INDIR))
goto read_mismatch;
(*merge) (ci_ptr->values, ci_ptr->num);
ci_ptr++;
}
if ((error = gcov_is_error ()))
goto read_error;
goto read_error;
}
if (tag)
@ -374,6 +331,37 @@ read_error:
return -1;
}
/* Store all TOP N counters where each has a dynamic length. */
static void
write_top_counters (const struct gcov_ctr_info *ci_ptr,
unsigned t_ix,
gcov_unsigned_t n_counts)
{
unsigned counters = n_counts / GCOV_TOPN_MEM_COUNTERS;
gcc_assert (n_counts % GCOV_TOPN_MEM_COUNTERS == 0);
unsigned pair_total = 0;
for (unsigned i = 0; i < counters; i++)
pair_total += ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 1];
unsigned disk_size = GCOV_TOPN_DISK_COUNTERS * counters + 2 * pair_total;
gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
GCOV_TAG_COUNTER_LENGTH (disk_size));
for (unsigned i = 0; i < counters; i++)
{
gcov_type pair_count = ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 1];
gcov_write_counter (ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i]);
gcov_write_counter (pair_count);
for (struct gcov_kvp *node
= (struct gcov_kvp *)ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 2];
node != NULL; node = node->next)
{
gcov_write_counter (node->value);
gcov_write_counter (node->count);
}
}
}
/* Write counters in GI_PTR and the summary in PRG to a gcda file. In
the case of appending to an existing file, SUMMARY_POS will be non-zero.
We will write the file starting from SUMMAY_POS. */
@ -433,11 +421,18 @@ write_one_data (const struct gcov_info *gi_ptr,
continue;
n_counts = ci_ptr->num;
gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
GCOV_TAG_COUNTER_LENGTH (n_counts));
c_ptr = ci_ptr->values;
while (n_counts--)
gcov_write_counter (*c_ptr++);
if (gi_ptr->merge[t_ix] == __gcov_merge_topn)
write_top_counters (ci_ptr, t_ix, n_counts);
else
{
gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
GCOV_TAG_COUNTER_LENGTH (n_counts));
c_ptr = ci_ptr->values;
while (n_counts--)
gcov_write_counter (*c_ptr++);
}
ci_ptr++;
}
if (buffered)
@ -476,9 +471,6 @@ dump_one_gcov (struct gcov_info *gi_ptr, struct gcov_filename *gf,
gcov_unsigned_t tag;
fn_buffer = 0;
/* Prune current counters before we merge them. */
prune_counters (gi_ptr);
error = gcov_exit_open_gcda_file (gi_ptr, gf);
if (error == -1)
return;

103
libgcc/libgcov-merge.c
View file

@ -86,86 +86,6 @@ __gcov_merge_time_profile (gcov_type *counters, unsigned n_counters)
#ifdef L_gcov_merge_topn
/* To merging of TOPN profiles.
counters[0] is the number of executions
for i in 0 ... TOPN-1
counters[2 * i + 1] is target
counters[2 * i + 2] is corresponding hitrate counter.
Because we prune counters only those with probability >= 1/TOPN are
present now.
We use sign of counters[0] to track whether the number of different
targets exceeds 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 ();
gcov_type *total = &counters[0];
++counters;
/* Negative value means that counter is missing some of values. */
if (all < 0)
*total = -(*total);
*total += all;
/* 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);
}
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
{
if (read_counters[2 * i + 1] == 0)
continue;
unsigned j;
int slot = 0;
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] < counters[2 * slot + 1])
slot = j;
}
if (j == GCOV_TOPN_VALUES)
{
gcov_type slot_count = counters[2 * slot + 1];
/* We found an empty slot. */
if (slot_count == 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
{
/* Here we are loosing some values. */
if (*total >= 0)
*total = -(*total);
if (read_counters[2 * i + 1] > slot_count)
{
counters[2 * slot] = read_counters[2 * i];
counters[2 * slot + 1] = read_counters[2 * i + 1];
}
else
counters[2 * slot + 1] -= read_counters[2 * i + 1];
}
}
}
}
/* 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
@ -175,13 +95,30 @@ merge_topn_values_set (gcov_type *counters)
-- 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));
gcc_assert (!(n_counters % GCOV_TOPN_MEM_COUNTERS));
for (unsigned i = 0; i < (n_counters / GCOV_TOPN_VALUES_COUNTERS); i++)
merge_topn_values_set (counters + (i * GCOV_TOPN_VALUES_COUNTERS));
for (unsigned i = 0; i < (n_counters / GCOV_TOPN_MEM_COUNTERS); i++)
{
/* First value is number of total executions of the profiler. */
gcov_type all = gcov_get_counter_ignore_scaling (-1);
gcov_type n = gcov_get_counter_ignore_scaling (-1);
counters[GCOV_TOPN_MEM_COUNTERS * i] += all;
for (unsigned j = 0; j < n; j++)
{
gcov_type value = gcov_get_counter_target ();
gcov_type count = gcov_get_counter_ignore_scaling (-1);
// TODO: we should use atomic here
gcov_topn_add_value (counters + GCOV_TOPN_MEM_COUNTERS * i, value,
count, 0, 0);
}
}
}
#endif /* L_gcov_merge_topn */

40
libgcc/libgcov-profiler.c
View file

@ -105,51 +105,13 @@ __gcov_pow2_profiler_atomic (gcov_type *counters, gcov_type value)
}
#endif
/* Tries to determine N most commons value among its inputs. */
static inline void
__gcov_topn_values_profiler_body (gcov_type *counters, gcov_type value,
int use_atomic)
{
if (use_atomic)
__atomic_fetch_add (&counters[0], 1, __ATOMIC_RELAXED);
else
counters[0]++;
++counters;
/* First try to find an existing value. */
int empty_counter = -1;
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
if (value == counters[2 * i])
{
if (use_atomic)
__atomic_fetch_add (&counters[2 * i + 1], GCOV_TOPN_VALUES,
__ATOMIC_RELAXED);
else
counters[2 * i + 1] += GCOV_TOPN_VALUES;
return;
}
else if (counters[2 * i + 1] <= 0)
empty_counter = i;
/* Find an empty slot for a new value. */
if (empty_counter != -1)
{
counters[2 * empty_counter] = value;
counters[2 * empty_counter + 1] = GCOV_TOPN_VALUES;
return;
}
/* We haven't found an empty slot, then decrement all
counter values by one. */
for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
if (use_atomic)
__atomic_fetch_sub (&counters[2 * i + 1], 1, __ATOMIC_RELAXED);
else
counters[2 * i + 1]--;
gcov_topn_add_value (counters, value, 1, use_atomic, 1);
}
#ifdef L_gcov_topn_values_profiler

87
libgcc/libgcov.h
View file

@ -373,6 +373,93 @@ gcov_get_counter_target (void)
#endif
}
/* Add VALUE to *COUNTER and make it with atomic operation
if USE_ATOMIC is true. */
static inline void
gcov_counter_add (gcov_type *counter, gcov_type value, int use_atomic)
{
if (use_atomic)
__atomic_fetch_add (counter, value, __ATOMIC_RELAXED);
else
*counter += value;
}
/* Set NODE to memory location COUNTER and make it with atomic operation
if USE_ATOMIC is true. */
static inline int
gcov_counter_set_if_null (gcov_type *counter, struct gcov_kvp *node,
int use_atomic)
{
if (use_atomic)
return !__sync_val_compare_and_swap (counter, NULL, (intptr_t)node);
else
{
*counter = (intptr_t)node;
return 1;
}
}
/* Add key value pair VALUE:COUNT to a top N COUNTERS. When INCREMENT_TOTAL
is true, add COUNT to total of the TOP counter. If USE_ATOMIC is true,
do it in atomic way. */
static inline void
gcov_topn_add_value (gcov_type *counters, gcov_type value, gcov_type count,
int use_atomic, int increment_total)
{
if (increment_total)
gcov_counter_add (&counters[0], 1, use_atomic);
struct gcov_kvp *prev_node = NULL;
struct gcov_kvp *minimal_node = NULL;
struct gcov_kvp *current_node = (struct gcov_kvp *)counters[2];
while (current_node)
{
if (current_node->value == value)
{
gcov_counter_add (&current_node->count, count, use_atomic);
return;
}
if (minimal_node == NULL
|| current_node->count < minimal_node->count)
minimal_node = current_node;
prev_node = current_node;
current_node = current_node->next;
}
if (counters[1] == GCOV_TOPN_MAXIMUM_TRACKED_VALUES)
{
if (--minimal_node->count < count)
{
minimal_node->value = value;
minimal_node->count = count;
}
}
else
{
struct gcov_kvp *new_node
= (struct gcov_kvp *)xmalloc (sizeof (struct gcov_kvp));
new_node->value = value;
new_node->count = count;
int success = 0;
if (!counters[2])
success = gcov_counter_set_if_null (&counters[2], new_node, use_atomic);
else if (prev_node && !prev_node->next)
success = gcov_counter_set_if_null ((gcov_type *)&prev_node->next,
new_node, use_atomic);
/* Increment number of nodes. */
if (success)
gcov_counter_add (&counters[1], 1, use_atomic);
}
}
#endif /* !inhibit_libc */
#endif /* GCC_LIBGCOV_H */