[PATCH v3 7/9] perf test coresight: Dismiss clang warning for unroll loop thread

Leo Yan
2025-10-06T16:21:59Z

clang-18.1.3 on Ubuntu 24.04.2 reports warning:

unroll_loop_thread.c:35:25: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
35 | : /* in */ [in] "r" (in)
| ^
unroll_loop_thread.c:39:1: warning: non-void function does not return a value [-Wreturn-type]
39 | }
| ^

Use the modifier "w" for 32-bit register access and return NULL at the
end of thread function.

Signed-off-by: Leo Yan <leo.yan@arm.com>
---
.../tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c b/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c
index 0fc7bf1a25af3607b40f091f62176134ddb7f9f6..8f4e1c985ca38ab545a05189432a14a6d888d34c 100644
--- a/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c
+++ b/tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c
@@ -20,7 +20,7 @@ static void *thrfn(void *arg)
for (i = 0; i < 10000; i++) {
asm volatile (
// force an unroll of thia add instruction so we can test long runs of code
-#define SNIP1 "add %[in], %[in], #1\n"
+#define SNIP1 "add %w[in], %w[in], #1\n"
// 10
#define SNIP2 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1
// 100
@@ -36,6 +36,8 @@ static void *thrfn(void *arg)
: /* clobber */
);
}
+
+ return NULL;
}

static pthread_t new_thr(void *(*fn) (void *arg), void *arg)

--
2.34.1