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Diffstat (limited to 'tools/build/feature/test-sync-compare-and-swap.c')
-rw-r--r--tools/build/feature/test-sync-compare-and-swap.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/tools/build/feature/test-sync-compare-and-swap.c b/tools/build/feature/test-sync-compare-and-swap.c
new file mode 100644
index 000000000..c34d4ca4a
--- /dev/null
+++ b/tools/build/feature/test-sync-compare-and-swap.c
@@ -0,0 +1,14 @@
+#include <stdint.h>
+
+volatile uint64_t x;
+
+int main(int argc, char *argv[])
+{
+ uint64_t old, new = argc;
+
+ argv = argv;
+ do {
+ old = __sync_val_compare_and_swap(&x, 0, 0);
+ } while (!__sync_bool_compare_and_swap(&x, old, new));
+ return old == new;
+}