--- a/src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp	Mon Sep 24 18:44:39 2018 +0200
+++ b/src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp	Mon Sep 24 18:19:46 2018 +0100
@@ -822,6 +822,15 @@
   return stub_start_addr;
 }
 
+void MacroAssembler::c2bool(Register x) {
+  // implements x == 0 ? 0 : 1
+  // note: must only look at least-significant byte of x
+  //       since C-style booleans are stored in one byte
+  //       only! (was bug)
+  tst(x, 0xff);
+  cset(x, Assembler::NE);
+}
+
 address MacroAssembler::ic_call(address entry, jint method_index) {
   RelocationHolder rh = virtual_call_Relocation::spec(pc(), method_index);
   // address const_ptr = long_constant((jlong)Universe::non_oop_word());

--- a/src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp	Mon Sep 24 18:44:39 2018 +0200
+++ b/src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp	Mon Sep 24 18:19:46 2018 +0100
@@ -782,6 +782,9 @@
 
   void resolve_jobject(Register value, Register thread, Register tmp);
 
+  // C 'boolean' to Java boolean: x == 0 ? 0 : 1
+  void c2bool(Register x);
+
   // oop manipulations
   void load_klass(Register dst, Register src);
   void store_klass(Register dst, Register src);

--- a/src/hotspot/cpu/aarch64/sharedRuntime_aarch64.cpp	Mon Sep 24 18:44:39 2018 +0200
+++ b/src/hotspot/cpu/aarch64/sharedRuntime_aarch64.cpp	Mon Sep 24 18:19:46 2018 +0100
@@ -1924,7 +1924,7 @@
 
   // Unpack native results.
   switch (ret_type) {
-  case T_BOOLEAN: __ ubfx(r0, r0, 0, 8);             break;
+  case T_BOOLEAN: __ c2bool(r0);                     break;
   case T_CHAR   : __ ubfx(r0, r0, 0, 16);            break;
   case T_BYTE   : __ sbfx(r0, r0, 0, 8);             break;
   case T_SHORT  : __ sbfx(r0, r0, 0, 16);            break;

--- a/src/hotspot/cpu/aarch64/templateInterpreterGenerator_aarch64.cpp	Mon Sep 24 18:44:39 2018 +0200
+++ b/src/hotspot/cpu/aarch64/templateInterpreterGenerator_aarch64.cpp	Mon Sep 24 18:19:46 2018 +0100
@@ -557,7 +557,7 @@
         BasicType type) {
     address entry = __ pc();
   switch (type) {
-  case T_BOOLEAN: __ uxtb(r0, r0);        break;
+  case T_BOOLEAN: __ c2bool(r0);         break;
   case T_CHAR   : __ uxth(r0, r0);       break;
   case T_BYTE   : __ sxtb(r0, r0);        break;
   case T_SHORT  : __ sxth(r0, r0);        break;