1 files changed, 15 insertions, 0 deletions
diff --git a/libgo/go/sync/cas.c b/libgo/go/sync/cas.c
new file mode 100644
index 000000000..ffcd133cb
--- /dev/null
+++ b/libgo/go/sync/cas.c
@@ -0,0 +1,15 @@
+/* cas.c -- implement sync.cas for Go.
+
+   Copyright 2009 The Go Authors. All rights reserved.
+   Use of this source code is governed by a BSD-style
+   license that can be found in the LICENSE file.  */
+
+#include <stdint.h>
+
+_Bool cas (int32_t *, int32_t, int32_t) asm ("libgo_sync.sync.cas");
+
+_Bool
+cas (int32_t *ptr, int32_t old, int32_t new)
+{
+  return __sync_bool_compare_and_swap (ptr, old, new);
+}