[PATCH 09/12] perf test: Add 'brstack' test workload

[Namhyung Kim <namhyung@kernel.org>]

The brstack is to run different kinds of branches repeatedly.  This is
necessary for brstack test case to verify if it has correct branch info.

  $ perf test -w brstack

I renamed the internal functions to have brstack_ prefix as it's too
generic name.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/tests/builtin-test.c      |  1 +
 tools/perf/tests/tests.h             |  1 +
 tools/perf/tests/workloads/Build     |  2 ++
 tools/perf/tests/workloads/brstack.c | 39 ++++++++++++++++++++++++++++
 4 files changed, 43 insertions(+)
 create mode 100644 tools/perf/tests/workloads/brstack.c

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 9acb7a93eeb9..69fa56939309 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -123,6 +123,7 @@ static struct test_workload *workloads[] = {
 	&workload__thloop,
 	&workload__leafloop,
 	&workload__sqrtloop,
+	&workload__brstack,
 };
 
 static int num_subtests(const struct test_suite *t)
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 18c40319e67c..dc96f59cac2e 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -204,5 +204,6 @@ DECLARE_WORKLOAD(noploop);
 DECLARE_WORKLOAD(thloop);
 DECLARE_WORKLOAD(leafloop);
 DECLARE_WORKLOAD(sqrtloop);
+DECLARE_WORKLOAD(brstack);
 
 #endif /* TESTS_H */
diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
index 1ca95cb0fdb5..c933cdcf91d1 100644
--- a/tools/perf/tests/workloads/Build
+++ b/tools/perf/tests/workloads/Build
@@ -4,5 +4,7 @@ perf-y += noploop.o
 perf-y += thloop.o
 perf-y += leafloop.o
 perf-y += sqrtloop.o
+perf-y += brstack.o
 
 CFLAGS_leafloop.o         = -g -O0 -fno-inline -fno-omit-frame-pointer
+CFLAGS_brstack.o          = -g -O0 -fno-inline
diff --git a/tools/perf/tests/workloads/brstack.c b/tools/perf/tests/workloads/brstack.c
new file mode 100644
index 000000000000..61c9a9f24b43
--- /dev/null
+++ b/tools/perf/tests/workloads/brstack.c
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <stdlib.h>
+#include "../tests.h"
+
+
+#define BENCH_RUNS 999999
+
+static volatile int cnt;
+
+static void brstack_bar(void) {
+}				/* return */
+
+static void brstack_foo(void) {
+	brstack_bar();		/* call */
+}				/* return */
+
+static void brstack_bench(void) {
+	void (*brstack_foo_ind)(void) = brstack_foo;
+
+	if ((cnt++) % 3)	/* branch (cond) */
+		brstack_foo();	/* call */
+	brstack_bar();		/* call */
+	brstack_foo_ind();	/* call (ind) */
+}
+
+static int brstack(int argc, const char **argv)
+{
+	if (argc > 0)
+		cnt = atoi(argv[0]);
+
+	while (1) {
+		if ((cnt++) > BENCH_RUNS)
+			break;
+		brstack_bench();/* call */
+	}			/* branch (uncond) */
+	return 0;
+}
+
+DEFINE_WORKLOAD(brstack);
-- 
2.38.1.493.g58b659f92b-goog