[v1,05/11] perf script: Add not taken event for branch stack

Commit Message

Leo Yan Feb. 5, 2025, 12:15 p.m. UTC

The branch stack has an existed field for printing mispredict, extend
the field for printing events and add support not-taken event.

Signed-off-by: Leo Yan <[e-mail]>
---
 tools/perf/builtin-script.c | 20 +++++++++++++-------
 tools/perf/util/branch.h    |  3 ++-
 2 files changed, 15 insertions(+), 8 deletions(-)

Patch

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index e7f79a3f1fd2..5e1c9a803d66 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -929,19 +929,25 @@  static int perf_sample__fprintf_start(struct perf_script *script,
 	return printed;
 }
 
-static inline char
-mispred_str(struct branch_entry *br)
+static inline size_t
+bstack_event_str(struct branch_entry *br, char *buf, size_t sz)
 {
-	if (!(br->flags.mispred  || br->flags.predicted))
-		return '-';
+	if (!(br->flags.mispred || br->flags.predicted || br->flags.not_taken))
+		return snprintf(buf, sz, "-");
 
-	return br->flags.predicted ? 'P' : 'M';
+	return snprintf(buf, sz, "%s%s",
+			br->flags.predicted ? "P" : "M",
+			br->flags.not_taken ? "N" : "");
 }
 
 static int print_bstack_flags(FILE *fp, struct branch_entry *br)
 {
-	return fprintf(fp, "/%c/%c/%c/%d/%s/%s ",
-		       mispred_str(br),
+	char events[16] = { 0 };
+	size_t pos;
+
+	pos = bstack_event_str(br, events, sizeof(events));
+	return fprintf(fp, "/%s/%c/%c/%d/%s/%s ",
+		       pos < 0 ? "-" : events,
 		       br->flags.in_tx ? 'X' : '-',
 		       br->flags.abort ? 'A' : '-',
 		       br->flags.cycles,
diff --git a/tools/perf/util/branch.h b/tools/perf/util/branch.h
index b80c12c74bbb..99338f26f5e5 100644
--- a/tools/perf/util/branch.h
+++ b/tools/perf/util/branch.h
@@ -18,6 +18,7 @@  struct branch_flags {
 		struct {
 			u64 mispred:1;
 			u64 predicted:1;
+			u64 not_taken:1;
 			u64 in_tx:1;
 			u64 abort:1;
 			u64 cycles:16;
@@ -25,7 +26,7 @@  struct branch_flags {
 			u64 spec:2;
 			u64 new_type:4;
 			u64 priv:3;
-			u64 reserved:31;
+			u64 reserved:30;
 		};
 	};
 };