--- a/src/hotspot/cpu/x86/x86_64.ad	Fri Nov 09 12:47:20 2018 +0530
+++ b/src/hotspot/cpu/x86/x86_64.ad	Fri Nov 09 10:38:07 2018 +0100
@@ -11925,9 +11925,9 @@
   ins_pipe(ialu_cr_reg_mem);
 %}
 
-instruct testB_mem_imm(rFlagsReg cr, memory mem, immI8 imm, immI0 zero)
-%{
-  match(Set cr (CmpI (AndI (LoadB mem) imm) zero));
+instruct testUB_mem_imm(rFlagsReg cr, memory mem, immU8 imm, immI0 zero)
+%{
+  match(Set cr (CmpI (AndI (LoadUB mem) imm) zero));
 
   ins_cost(125);
   format %{ "testb   $mem, $imm" %}