From: Simon Marlow <marlowsd@gmail.com>
Date: Fri, 6 Feb 2009 13:01:30 +0000 (+0000)
Subject: add a single-threaded version of cas()
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=5f7079b97e322fd84e99adb686c86afe6d7c8231;p=ghc-hetmet.git

add a single-threaded version of cas()
---

diff --git a/includes/SMP.h b/includes/SMP.h
index 5d74667..49bc336 100644
--- a/includes/SMP.h
+++ b/includes/SMP.h
@@ -218,6 +218,17 @@ xchg(StgPtr p, StgWord w)
     return old;
 }
 
+STATIC_INLINE StgWord
+cas(StgVolatilePtr p, StgWord o, StgWord n)
+{
+    StgWord result;
+    result = *p;
+    if (result == o) {
+        *p = n;
+    }
+    return result;
+}
+
 #endif /* !THREADED_RTS */
 
 #endif /* SMP_H */