diff -r be620a591379 -r 8e22715afabc src/hotspot/cpu/x86/c1_Runtime1_x86.cpp
--- a/src/hotspot/cpu/x86/c1_Runtime1_x86.cpp	Mon Oct 30 21:23:10 2017 +0100
+++ b/src/hotspot/cpu/x86/c1_Runtime1_x86.cpp	Mon Nov 06 18:53:38 2017 +0100
@@ -1675,16 +1675,23 @@
 
     case g1_post_barrier_slow_id:
       {
+        BarrierSet* bs = Universe::heap()->barrier_set();
+        if (bs->kind() != BarrierSet::G1SATBCT &&
+            bs->kind() != BarrierSet::G1SATBCTLogging) {
+          __ movptr(rax, (int)id);
+          __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, unimplemented_entry), rax);
+          __ should_not_reach_here();
+          break;
+        }
+
+        CardTableModRefBS* ct = barrier_set_cast<CardTableModRefBS>(bs);
+        assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");
+
         StubFrame f(sasm, "g1_post_barrier", dont_gc_arguments);
 
-
         // arg0: store_address
         Address store_addr(rbp, 2*BytesPerWord);
 
-        CardTableModRefBS* ct =
-          barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
-        assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");
-
         Label done;
         Label enqueued;
         Label runtime;