Currently get_most_common_single_value could only return the max hist
<value, count>, add sort after reading from disk, then it return nth value
in later use. Rename it to get_nth_most_common_value.
Hi Martin,
Thanks for your review, v4 Changes as below:
1. Use decrease bubble sort.
BTW, I have a question about hist->hvalue.counters[2], when will it become
-1, please? Thanks. Currently, if it is -1, the function will return false.
gcc/ChangeLog:
2019-07-15 Xiong Hu Luo <luo...@linux.ibm.com>
* ipa-profile.c (get_most_common_single_value): Use
get_nth_most_common_value.
* profile.c (sort_hist_value): New function.
(compute_value_histograms): Call sort_hist_value to sort the
values after loading from disk.
* value-prof.c (get_most_common_single_value): Rename to ...
get_nth_most_common_value. Add input params n, return
the n_th value and count.
(gimple_divmod_fixed_value_transform): Use
get_nth_most_common_value.
(gimple_ic_transform): Likewise.
(gimple_stringops_transform): Likewise.
* value-prof.h (get_most_common_single_value): Add input params
n, default to 0.
---
gcc/ipa-profile.c | 4 ++--
gcc/profile.c | 44 +++++++++++++++++++++++++++++++++++++++
gcc/value-prof.c | 53 ++++++++++++++++++++---------------------------
gcc/value-prof.h | 9 ++++----
4 files changed, 73 insertions(+), 37 deletions(-)
diff --git a/gcc/ipa-profile.c b/gcc/ipa-profile.c
index 1fb939b73d0..970dba39c80 100644
--- a/gcc/ipa-profile.c
+++ b/gcc/ipa-profile.c
@@ -192,8 +192,8 @@ ipa_profile_generate_summary (void)
if (h)
{
gcov_type val, count, all;
- if (get_most_common_single_value (NULL, "indirect call",
- h, &val, &count, &all))
+ if (get_nth_most_common_value (NULL, "indirect call", h,
+ &val, &count, &all))
{
struct cgraph_edge * e = node->get_edge (stmt);
if (e && !e->indirect_unknown_callee)
diff --git a/gcc/profile.c b/gcc/profile.c
index 441cb8eb183..ae21b1192a0 100644
--- a/gcc/profile.c
+++ b/gcc/profile.c
@@ -743,6 +743,44 @@ compute_branch_probabilities (unsigned cfg_checksum,
unsigned lineno_checksum)
free_aux_for_blocks ();
}
+ /* Sort the histogram value and count for TOPN and INDIR_CALL type. */
+
+static bool
+sort_hist_value (histogram_value hist)
+{
+
+ if (hist->hvalue.counters[2] == -1)
+ return false;
+
+ gcc_assert (hist->type == HIST_TYPE_TOPN_VALUES
+ || hist->type == HIST_TYPE_INDIR_CALL);
+
+ gcc_assert (hist->n_counters == GCOV_TOPN_VALUES_COUNTERS);
+
+ unsigned i, j;
+ bool swapped = true;
+ /* Hist value is organized as:
+ [counter0 value1 counter1 value2 counter2 value3 counter3 value4 counter4]
+ Use decrese 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 (i = 0; i < GCOV_TOPN_VALUES - 1 && swapped; i++)
+ {
+ swapped = false;
+ for (j = 0; j < GCOV_TOPN_VALUES - 1 - i; j++)
+ {
+ gcov_type *p = &hist->hvalue.counters[2 * j + 1];
+ if (p[1] < p[3] || (p[1] == p[3] && p[0] < p[2]))
+ {
+ std::swap (p[0], p[2]);
+ std::swap (p[1], p[3]);
+ swapped = true;
+ }
+ }
+ }
+
+ return true;
+}
/* Load value histograms values whose description is stored in VALUES array
from .gcda file.
@@ -808,6 +846,12 @@ compute_value_histograms (histogram_values values,
unsigned cfg_checksum,
else
hist->hvalue.counters[j] = 0;
+ if (hist->type == HIST_TYPE_TOPN_VALUES
+ || hist->type == HIST_TYPE_INDIR_CALL)
+ {
+ sort_hist_value (hist);
+ }
+
/* Time profiler counter is not related to any statement,
so that we have to read the counter and set the value to
the corresponding call graph node. */
diff --git a/gcc/value-prof.c b/gcc/value-prof.c
index 32e6ddd8165..759458868a8 100644
--- a/gcc/value-prof.c
+++ b/gcc/value-prof.c
@@ -713,45 +713,38 @@ gimple_divmod_fixed_value (gassign *stmt, tree value,
profile_probability prob,
return tmp2;
}
-/* Return most common value of TOPN_VALUE histogram. If
- there's a unique value, return true and set VALUE and COUNT
+/* Return the n-th value count of TOPN_VALUE histogram. If
+ there's a value, return true and set VALUE and COUNT
arguments. */
bool
-get_most_common_single_value (gimple *stmt, const char *counter_type,
- histogram_value hist,
- gcov_type *value, gcov_type *count,
- gcov_type *all)
+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)
{
if (hist->hvalue.counters[2] == -1)
return false;
+ gcc_assert (n < GCOV_TOPN_VALUES);
+
*count = 0;
*value = 0;
gcov_type read_all = hist->hvalue.counters[0];
- for (unsigned i = 0; i < GCOV_TOPN_VALUES; i++)
- {
- gcov_type v = hist->hvalue.counters[2 * i + 1];
- gcov_type c = hist->hvalue.counters[2 * i + 2];
-
- /* Indirect calls can't be vereified. */
- if (stmt && check_counter (stmt, counter_type, &c, &read_all,
- gimple_bb (stmt)->count))
- return false;
+ gcov_type v = hist->hvalue.counters[2 * n + 1];
+ gcov_type c = hist->hvalue.counters[2 * n + 2];
- *all = read_all;
+ /* Indirect calls can't be verified. */
+ if (stmt
+ && check_counter (stmt, counter_type, &c, &read_all,
+ gimple_bb (stmt)->count))
+ return false;
- if (c > *count)
- {
- *value = v;
- *count = c;
- }
- else if (c == *count && v > *value)
- *value = v;
- }
+ *all = read_all;
+ *value = v;
+ *count = c;
return true;
}
@@ -784,8 +777,8 @@ gimple_divmod_fixed_value_transform (gimple_stmt_iterator
*si)
if (!histogram)
return false;
- if (!get_most_common_single_value (stmt, "divmod", histogram, &val, &count,
- &all))
+ if (!get_nth_most_common_value (stmt, "divmod", histogram, &val, &count,
+ &all))
return false;
value = histogram->hvalue.value;
@@ -1439,8 +1432,8 @@ gimple_ic_transform (gimple_stmt_iterator *gsi)
if (!histogram)
return false;
- if (!get_most_common_single_value (NULL, "indirect call", histogram, &val,
- &count, &all))
+ if (!get_nth_most_common_value (NULL, "indirect call", histogram, &val,
+ &count, &all))
return false;
if (4 * count <= 3 * all)
@@ -1658,8 +1651,8 @@ gimple_stringops_transform (gimple_stmt_iterator *gsi)
if (!histogram)
return false;
- if (!get_most_common_single_value (stmt, "stringops", histogram, &val,
- &count, &all))
+ if (!get_nth_most_common_value (stmt, "stringops", histogram, &val, &count,
+ &all))
return false;
gimple_remove_histogram_value (cfun, stmt, histogram);
diff --git a/gcc/value-prof.h b/gcc/value-prof.h
index ca846d08cbd..1078722163b 100644
--- a/gcc/value-prof.h
+++ b/gcc/value-prof.h
@@ -89,11 +89,10 @@ void free_histograms (function *);
void stringop_block_profile (gimple *, unsigned int *, HOST_WIDE_INT *);
gcall *gimple_ic (gcall *, struct cgraph_node *, profile_probability);
bool check_ic_target (gcall *, struct cgraph_node *);
-bool get_most_common_single_value (gimple *stmt, const char *counter_type,
- histogram_value hist,
- gcov_type *value, gcov_type *count,
- gcov_type *all);
-
+bool 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 = 0);
/* In tree-profile.c. */
extern void gimple_init_gcov_profiler (void);
--
2.22.0.428.g6d5b264208
