1 files changed, 6 insertions, 9 deletions
diff --git a/rts/PrimOps.cmm b/rts/PrimOps.cmm
index b13e05ce87..710330714e 100644
--- a/rts/PrimOps.cmm
+++ b/rts/PrimOps.cmm
@@ -206,28 +206,25 @@ stg_unsafeThawArrayzh ( gcptr arr )
   }
 }
 
-stg_casArrayzh
+stg_casArrayzh ( gcptr arr, W_ ind, gcptr old, gcptr new )
 /* MutableArray# s a -> Int# -> a -> a -> State# s -> (# State# s, Int#, a #) */
 {
-    W_ arr, p, ind, old, new, h, len;
-    arr = R1; // anything else?
-    ind = R2;
-    old = R3;
-    new = R4;
+    gcptr p, h;
+    W_ len;
 
     p = arr + SIZEOF_StgMutArrPtrs + WDS(ind);
-    (h) = foreign "C" cas(p, old, new) [];
+    (h) = ccall cas(p, old, new);
     
     if (h != old) {
         // Failure, return what was there instead of 'old':
-        RET_NP(1,h);
+        return (1,h);
     } else {
         // Compare and Swap Succeeded:
 	SET_HDR(arr, stg_MUT_ARR_PTRS_DIRTY_info, CCCS);
 	len = StgMutArrPtrs_ptrs(arr);
 	// The write barrier.  We must write a byte into the mark table:
 	I8[arr + SIZEOF_StgMutArrPtrs + WDS(len) + (ind >> MUT_ARR_PTRS_CARD_BITS )] = 1;
-        RET_NP(0,h);
+        return (0,h);
     }
 }