Restrict what kind of statements are used for auto-profile

[Jan Hubicka]

Restrict what kind of statements are used for auto-profile

When building profile of walk_tree_1 during autoprofiledbootstrap we produce
non-zero counts to call of tree_check_failed because location of INLINE_ENTRY
debug statement is misplaced.  Auto-profile already knows it should skip
clobbers since their locations will never go into debug info.  This patch extend
it to all kind of debug statement except for DEBUG_BEGIN_STMT, nops, labels
and predict.

autoprofilebootstrapped/regtested x86_64-linux.

gcc/ChangeLog:

        * auto-profile.cc (stmt_loc_used_by_debug_info): New function.
        (autofdo_source_profile::get_count_info): Use it.
        (afdo_set_bb_count): Likewise.
        (afdo_vpt_for_early_inline): Likewise.

diff --git a/gcc/auto-profile.cc b/gcc/auto-profile.cc
index e71689de308..46076486e5f 100644
--- a/gcc/auto-profile.cc
+++ b/gcc/auto-profile.cc
@@ -136,6 +139,24 @@ maybe_hot_afdo_count_p (profile_count count)
   return count.ipa ().to_gcov_type () >= afdo_hot_bb_threshod;
 }
 
+/* Return true if location of STMT may be expressed by debug info.  */
+
+static bool
+stmt_loc_used_by_debug_info (gimple *stmt)
+{
+  /* Only inline_entry and gimple_bind's locations
+     are not output into debug output.  */
+  if (is_gimple_debug (stmt))
+    return gimple_debug_begin_stmt_p (stmt);
+  if (gimple_code (stmt) == GIMPLE_LABEL
+      || gimple_code (stmt) == GIMPLE_NOP
+      || gimple_code (stmt) == GIMPLE_PREDICT)
+    return false;
+  if (gimple_clobber_p (stmt))
+    return false;
+  return true;
+}
+
 namespace autofdo
 {
 
@@ -2417,6 +2533,7 @@ bool
 autofdo_source_profile::get_count_info (gimple *stmt, count_info *info,
                                        cgraph_node *node) const
 {
+  gcc_checking_assert (stmt_loc_used_by_debug_info (stmt));
   return get_count_info (gimple_location (stmt), info, node);
 }
 
@@ -2967,7 +3084,7 @@ afdo_set_bb_count (basic_block bb, hash_set <basic_block> 
&zero_bbs)
     {
       count_info info;
       gimple *stmt = gsi_stmt (gsi);
-      if (gimple_clobber_p (stmt))
+      if (!stmt_loc_used_by_debug_info (stmt))
        continue;
       if (afdo_source_profile->get_count_info (stmt, &info))
        {
@@ -4135,8 +4341,10 @@ afdo_vpt_for_early_inline (cgraph_node *node)
       for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
           !gsi_end_p (gsi); gsi_next (&gsi))
        {
-         autofdo::count_info info;
          gimple *stmt = gsi_stmt (gsi);
+         if (!stmt_loc_used_by_debug_info (stmt))
+           continue;
+         autofdo::count_info info;
          if (autofdo::afdo_source_profile->get_count_info (stmt, &info, node))
            bb_count = MAX (bb_count, info.count);
        }