--- old/src/hotspot/os_cpu/linux_x86/gc/z/zArguments_linux_x86.cpp	2019-01-08 21:12:25.075951685 +0100
+++ new/src/hotspot/os_cpu/linux_x86/gc/z/zArguments_linux_x86.cpp	2019-01-08 21:12:24.793939571 +0100
@@ -28,6 +28,7 @@
 #include "utilities/debug.hpp"
 
 void ZArguments::initialize_platform() {
+#if COMPILER2
   // The C2 barrier slow path expects vector registers to be least
   // 16 bytes wide, which is the minimum width available on all
   // x86-64 systems. However, the user could have speficied a lower
@@ -37,4 +38,5 @@
     warning("ZGC requires MaxVectorSize to be at least 16");
     FLAG_SET_DEFAULT(MaxVectorSize, 16);
   }
+#endif
 }