diff --git a/test/CFrontend/2008-03-05-syncPtr.c b/test/CFrontend/2008-03-05-syncPtr.c
index 6d5be5d..b371c34 100644
--- a/test/CFrontend/2008-03-05-syncPtr.c
+++ b/test/CFrontend/2008-03-05-syncPtr.c
@@ -1,4 +1,6 @@
 // RUN: %llvmgcc %s -S -emit-llvm -o - | grep llvm.atomic
+// XFAIL: powerpc|sparc-sun-solaris2|arm|ia64
+// Feature currently implemented only for x86 and alpha.
 
 int* foo(int** a, int* b, int* c) {
 return __sync_val_compare_and_swap (a, b, c);