perf script: Add not taken event for branches

Some hardware (e.g., Arm SPE) can trace the not taken event for
branches.  Add a flag for this event and support printing it.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Link: https://lore.kernel.org/r/20250304111240.3378214-5-leo.yan@arm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/util/event.h

@@ -67,9 +67,10 @@ enum {
 	PERF_IP_FLAG_INTR_DISABLE	= 1ULL << 13,
 	PERF_IP_FLAG_INTR_TOGGLE	= 1ULL << 14,
 	PERF_IP_FLAG_BRANCH_MISS	= 1ULL << 15,
+	PERF_IP_FLAG_NOT_TAKEN		= 1ULL << 16,
 };
 
-#define PERF_IP_FLAG_CHARS "bcrosyiABExghDtm"
+#define PERF_IP_FLAG_CHARS "bcrosyiABExghDtmn"
 
 #define PERF_ADDITIONAL_STATE_MASK	\
 	(PERF_IP_FLAG_IN_TX |		\
@@ -91,7 +92,8 @@ enum {
 	PERF_IP_FLAG_VMEXIT)
 
 #define PERF_IP_FLAG_BRACH_EVENT_MASK	\
-	PERF_IP_FLAG_BRANCH_MISS
+	(PERF_IP_FLAG_BRANCH_MISS |	\
+	 PERF_IP_FLAG_NOT_TAKEN)
 
 #define PERF_MEM_DATA_SRC_NONE \
 	(PERF_MEM_S(OP, NA) |\

tools/perf/util/trace-event-scripting.c

@@ -317,6 +317,7 @@ static const struct {
 	const char *name;
 } branch_events[] = {
 	{PERF_IP_FLAG_BRANCH_MISS, "miss"},
+	{PERF_IP_FLAG_NOT_TAKEN, "not_taken"},
 	{0, NULL}
 };