1 files changed, 99 insertions, 0 deletions

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 277947a669b..cb17e2a8c6e 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -244,6 +244,8 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template)
 			he->ms.map->referenced = true;
 		if (symbol_conf.use_callchain)
 			callchain_init(he->callchain);
+
+		INIT_LIST_HEAD(&he->pairs.node);
 	}
 
 	return he;
@@ -410,6 +412,7 @@ hist_entry__collapse(struct hist_entry *left, struct hist_entry *right)
 
 void hist_entry__free(struct hist_entry *he)
 {
+	free(he->branch_info);
 	free(he);
 }
 
@@ -713,3 +716,99 @@ void hists__inc_nr_events(struct hists *hists, u32 type)
 	++hists->stats.nr_events[0];
 	++hists->stats.nr_events[type];
 }
+
+static struct hist_entry *hists__add_dummy_entry(struct hists *hists,
+						 struct hist_entry *pair)
+{
+	struct rb_node **p = &hists->entries.rb_node;
+	struct rb_node *parent = NULL;
+	struct hist_entry *he;
+	int cmp;
+
+	while (*p != NULL) {
+		parent = *p;
+		he = rb_entry(parent, struct hist_entry, rb_node);
+
+		cmp = hist_entry__cmp(pair, he);
+
+		if (!cmp)
+			goto out;
+
+		if (cmp < 0)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	he = hist_entry__new(pair);
+	if (he) {
+		memset(&he->stat, 0, sizeof(he->stat));
+		he->hists = hists;
+		rb_link_node(&he->rb_node, parent, p);
+		rb_insert_color(&he->rb_node, &hists->entries);
+		hists__inc_nr_entries(hists, he);
+	}
+out:
+	return he;
+}
+
+static struct hist_entry *hists__find_entry(struct hists *hists,
+					    struct hist_entry *he)
+{
+	struct rb_node *n = hists->entries.rb_node;
+
+	while (n) {
+		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
+		int64_t cmp = hist_entry__cmp(he, iter);
+
+		if (cmp < 0)
+			n = n->rb_left;
+		else if (cmp > 0)
+			n = n->rb_right;
+		else
+			return iter;
+	}
+
+	return NULL;
+}
+
+/*
+ * Look for pairs to link to the leader buckets (hist_entries):
+ */
+void hists__match(struct hists *leader, struct hists *other)
+{
+	struct rb_node *nd;
+	struct hist_entry *pos, *pair;
+
+	for (nd = rb_first(&leader->entries); nd; nd = rb_next(nd)) {
+		pos  = rb_entry(nd, struct hist_entry, rb_node);
+		pair = hists__find_entry(other, pos);
+
+		if (pair)
+			hist__entry_add_pair(pos, pair);
+	}
+}
+
+/*
+ * Look for entries in the other hists that are not present in the leader, if
+ * we find them, just add a dummy entry on the leader hists, with period=0,
+ * nr_events=0, to serve as the list header.
+ */
+int hists__link(struct hists *leader, struct hists *other)
+{
+	struct rb_node *nd;
+	struct hist_entry *pos, *pair;
+
+	for (nd = rb_first(&other->entries); nd; nd = rb_next(nd)) {
+		pos = rb_entry(nd, struct hist_entry, rb_node);
+
+		if (!hist_entry__has_pairs(pos)) {
+			pair = hists__add_dummy_entry(leader, pos);
+			if (pair == NULL)
+				return -1;
+			hist__entry_add_pair(pair, pos);
+		}
+	}
+
+	return 0;
+}