--- a/src/hotspot/share/opto/compile.cpp	Fri Dec 15 10:26:45 2017 -0800
+++ b/src/hotspot/share/opto/compile.cpp	Fri Dec 15 10:44:06 2017 -0800
@@ -1094,6 +1094,7 @@
   _major_progress = true; // start out assuming good things will happen
   set_has_unsafe_access(false);
   set_max_vector_size(0);
+  set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   set_decompile_count(0);