X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fx86-64-arch.h;h=2085503d84c1700761963268de09f94819f867de;hb=e4542bc034db18cf98f005b2dac53a6d7d5c7260;hp=90b51508b42843b181a3508a170ac7982ed91fcf;hpb=6208e9ee15dbdea405f53d70046f034fc3e0777b;p=sbcl.git

diff --git a/src/runtime/x86-64-arch.h b/src/runtime/x86-64-arch.h
index 90b5150..2085503 100644
--- a/src/runtime/x86-64-arch.h
+++ b/src/runtime/x86-64-arch.h
@@ -43,4 +43,15 @@ release_spinlock(volatile lispobj *word)
     *word=0;
 }
 
+static inline lispobj
+swap_lispobjs(volatile lispobj *dest, lispobj value)
+{
+    lispobj old_value;
+    asm ("lock xchg %0,(%1)"
+         : "=r" (old_value)
+         : "r" (dest), "0" (value)
+         : "memory");
+    return old_value;
+}
+
 #endif /* _X86_64_ARCH_H */