Merge "libtimeinstate: fix unused variable warning" into main am: 17af174627 am: 48c808bd55

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/3077312

Change-Id: Id2ca7be7835bf8f182e4ff2fdabe7aac90724549
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/libs/cputimeinstate/testtimeinstate.cpp b/libs/cputimeinstate/testtimeinstate.cpp
index 6ccc6ca..81f6a58 100644
--- a/libs/cputimeinstate/testtimeinstate.cpp
+++ b/libs/cputimeinstate/testtimeinstate.cpp
@@ -40,6 +40,9 @@
 static constexpr uint64_t NSEC_PER_SEC = 1000000000;
 static constexpr uint64_t NSEC_PER_YEAR = NSEC_PER_SEC * 60 * 60 * 24 * 365;
 
+// Declare busy loop variable globally to prevent removal during optimization
+static long sum __attribute__((used)) = 0;
+
 using std::vector;
 
 class TimeInStateTest : public testing::Test {
@@ -576,7 +579,7 @@
 
 // Keeps CPU busy with some number crunching
 void useCpu() {
-    long sum = 0;
+    sum = 0;
     for (int i = 0; i < 100000; i++) {
         sum *= i;
     }