Generalize get_most_common_single_value to return n_th value & count

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.

gcc/ChangeLog:

2019-07-15  Xiong Hu Luo  <luoxhu@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.

From-SVN: r273789

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 16757b0..ef12578 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,20 @@
+2019-07-25  Xiong Hu Luo  <luoxhu@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.
+
 2019-07-25  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/91236

diff --git a/gcc/ipa-profile.c b/gcc/ipa-profile.c
index 1fb939b..970dba3 100644 (file)
--- 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 441cb8e..6c8127a 100644 (file)
--- a/gcc/profile.c
+++ b/gcc/profile.c
@@ -743,6 +743,42 @@ 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 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);
+
+  /* Hist value is organized as:
+     [total_executions, value1, counter1, ..., value4, counter4]
+     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++)
+       {
+         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;
+           }
+       }
+      if (!swapped)
+       break;
+    }
+}
 /* Load value histograms values whose description is stored in VALUES array
    from .gcda file.  
 
@@ -808,6 +844,10 @@ 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_values (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 32e6ddd..7594588 100644 (file)
--- 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 ca846d0..1078722 100644 (file)
--- 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);