From 871e5ada6d53d5eb495cc9f323983f347487c1b2 Mon Sep 17 00:00:00 2001
From: Martin Liska <mliska@suse.cz>
Date: Fri, 31 Jan 2020 13:10:14 +0100
Subject: Make TOPN counter dynamically allocated.

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.
---
 libgcc/libgcov.h | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)

(limited to 'libgcc/libgcov.h')

diff --git a/libgcc/libgcov.h b/libgcc/libgcov.h
index b248690..bc38f4d 100644
--- a/libgcc/libgcov.h
+++ b/libgcc/libgcov.h
@@ -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 */
-- 
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