2008-08-18 Paul Yuan <yingbo.com@gmail.com>

	    Vinodha Ramasamy  <vinodha@google.com>

	* cgraph.c (cgraph_edge): Handle inconsistent counts when setting
	count_scale.
	* value-prof.c (check_counter): Fix the counter if
	flag_profile_correction is true.
	(tree_divmod_fixed_value_transform, tree_mod_pow2_value_transform,
	tree_mod_subtract_transform):
	Follow check_counter parameter change.
	* common.opt (fprofile-correction): New option.
	* mcf.c: New file.
	* profile.c (edge_info, EDGE_INFO): Moved to new file profile.h.
	(sum_edge_counts, is_edge_inconsistent, correct_negative_edge_counts,
	is_inconsistent, set_bb_counts, read_profile_edge_counts): New
	functions.
	(compute_branch_probabilities): Refactored. Invokes mcf_smooth_cfg if
	flag_profile_correction is set.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@139208 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 40 insertions, 13 deletions

diff --git a/gcc/value-prof.c b/gcc/value-prof.c
index 7f776ccaf89..f3522f6dcb5 100644
--- a/gcc/value-prof.c
+++ b/gcc/value-prof.c
@@ -453,18 +453,32 @@ free_histograms (void)
    somehow.  */
 
 static bool
-check_counter (gimple stmt, const char *name, gcov_type all, gcov_type bb_count)
+check_counter (gimple stmt, const char * name,
+	       gcov_type *count, gcov_type *all, gcov_type bb_count)
 {
-  if (all != bb_count)
+  if (*all != bb_count || *count > *all)
     {
       location_t locus;
       locus = (stmt != NULL)
-	       ? gimple_location (stmt)
-	       : DECL_SOURCE_LOCATION (current_function_decl);
-      error ("%HCorrupted value profile: %s profiler overall count (%d) "
-	     "does not match BB count (%d)", &locus, name, (int)all,
-	     (int)bb_count);
-      return true;
+              ? gimple_location (stmt)
+              : DECL_SOURCE_LOCATION (current_function_decl);
+      if (flag_profile_correction)
+        {
+	  inform ("%HCorrecting inconsistent value profile: "
+		  "%s profiler overall count (%d) does not match BB count "
+                  "(%d)", &locus, name, (int)all, (int)bb_count);
+	  *all = bb_count;
+	  if (*count > *all)
+            *count = *all;
+	  return false;
+	}
+      else
+	{
+	  error ("%HCorrupted value profile: %s profiler overall count (%d) "
+                 "does not match BB count (%d)", &locus, name, (int)all,
+                 (int)bb_count);
+	  return true;
+	}
     }
 
   return false;
@@ -658,7 +672,7 @@ gimple_divmod_fixed_value_transform (gimple_stmt_iterator *si)
       || !maybe_hot_bb_p (gimple_bb (stmt)))
     return false;
 
-  if (check_counter (stmt, "value", all, gimple_bb (stmt)->count))
+  if (check_counter (stmt, "value", &count, &all, gimple_bb (stmt)->count))
     return false;
 
   /* Compute probability of taking the optimal path.  */
@@ -818,7 +832,7 @@ gimple_mod_pow2_value_transform (gimple_stmt_iterator *si)
   /* Compute probability of taking the optimal path.  */
   all = count + wrong_values;
 
-  if (check_counter (stmt, "pow2", all, gimple_bb (stmt)->count))
+  if (check_counter (stmt, "pow2", &count, &all, gimple_bb (stmt)->count))
     return false;
 
   if (all > 0)
@@ -982,12 +996,17 @@ gimple_mod_subtract_transform (gimple_stmt_iterator *si)
   count2 = histogram->hvalue.counters[1];
 
   /* Compute probability of taking the optimal path.  */
-  if (check_counter (stmt, "interval", all, gimple_bb (stmt)->count))
+  if (check_counter (stmt, "interval", &count1, &all, gimple_bb (stmt)->count))
     {
       gimple_remove_histogram_value (cfun, stmt, histogram);
       return false;
     }
 
+  if (flag_profile_correction && count1 + count2 > all)
+      all = count1 + count2;
+
+  gcc_assert (count1 + count2 <= all);
+
   /* We require that we use just subtractions in at least 50% of all
      evaluations.  */
   count = 0;
@@ -1160,7 +1179,7 @@ static bool
 gimple_ic_transform (gimple stmt)
 {
   histogram_value histogram;
-  gcov_type val, count, all;
+  gcov_type val, count, all, bb_all;
   gcov_type prob;
   tree callee;
   gimple modify;
@@ -1186,6 +1205,14 @@ gimple_ic_transform (gimple stmt)
   if (4 * count <= 3 * all)
     return false;
 
+  bb_all = gimple_bb (stmt)->count;
+  /* The order of CHECK_COUNTER calls is important - 
+     since check_counter can correct the third parameter
+     and we want to make count <= all <= bb_all. */
+  if ( check_counter (stmt, "ic", &all, &bb_all, bb_all)
+      || check_counter (stmt, "ic", &count, &all, all))
+    return false;
+
   if (all > 0)
     prob = (count * REG_BR_PROB_BASE + all / 2) / all;
   else
@@ -1372,7 +1399,7 @@ gimple_stringops_transform (gimple_stmt_iterator *gsi)
      at least 80% of time.  */
   if ((6 * count / 5) < all || !maybe_hot_bb_p (gimple_bb (stmt)))
     return false;
-  if (check_counter (stmt, "value", all, gimple_bb (stmt)->count))
+  if (check_counter (stmt, "value", &count, &all, gimple_bb (stmt)->count))
     return false;
   if (all > 0)
     prob = (count * REG_BR_PROB_BASE + all / 2) / all;