--- a/src/hotspot/cpu/s390/c1_LIRGenerator_s390.cpp	Sun Oct 29 18:13:18 2017 -0700
+++ b/src/hotspot/cpu/s390/c1_LIRGenerator_s390.cpp	Mon Oct 30 17:14:39 2017 +0100
@@ -277,7 +277,7 @@
     length.set_instruction(x->length());
     length.load_item();
   }
-  if (needs_store_check) {
+  if (needs_store_check || x->check_boolean()) {
     value.load_item();
   } else {
     value.load_for_store(x->elt_type());
@@ -327,11 +327,14 @@
     // Needs GC write barriers.
     pre_barrier(LIR_OprFact::address(array_addr), LIR_OprFact::illegalOpr /* pre_val */,
                 true /* do_load */, false /* patch */, NULL);
-    __ move(value.result(), array_addr, null_check_info);
-    // Seems to be a precise.
+  }
+
+  LIR_Opr result = maybe_mask_boolean(x, array.result(), value.result(), null_check_info);
+  __ move(result, array_addr, null_check_info);
+
+  if (obj_store) {
+    // Precise card mark
     post_barrier(LIR_OprFact::address(array_addr), value.result());
-  } else {
-    __ move(value.result(), array_addr, null_check_info);
   }
 }
 

--- a/src/hotspot/cpu/s390/interp_masm_s390.cpp	Sun Oct 29 18:13:18 2017 -0700
+++ b/src/hotspot/cpu/s390/interp_masm_s390.cpp	Mon Oct 30 17:14:39 2017 +0100
@@ -843,6 +843,38 @@
   verify_oop(Z_tos, state);
 }
 
+void InterpreterMacroAssembler::narrow(Register result, Register ret_type) {
+  get_method(ret_type);
+  z_lg(ret_type, Address(ret_type, in_bytes(Method::const_offset())));
+  z_lb(ret_type, Address(ret_type, in_bytes(ConstMethod::result_type_offset())));
+
+  Label notBool, notByte, notChar, done;
+
+  // common case first
+  compareU32_and_branch(ret_type, T_INT, bcondEqual, done);
+
+  compareU32_and_branch(ret_type, T_BOOLEAN, bcondNotEqual, notBool);
+  z_nilf(result, 0x1);
+  z_bru(done);
+
+  bind(notBool);
+  compareU32_and_branch(ret_type, T_BYTE, bcondNotEqual, notByte);
+  z_lbr(result, result);
+  z_bru(done);
+
+  bind(notByte);
+  compareU32_and_branch(ret_type, T_CHAR, bcondNotEqual, notChar);
+  z_nilf(result, 0xffff);
+  z_bru(done);
+
+  bind(notChar);
+  // compareU32_and_branch(ret_type, T_SHORT, bcondNotEqual, notShort);
+  z_lhr(result, result);
+
+  // Nothing to do for T_INT
+  bind(done);
+}
+
 // remove activation
 //
 // Unlock the receiver if this is a synchronized method.

--- a/src/hotspot/cpu/s390/interp_masm_s390.hpp	Sun Oct 29 18:13:18 2017 -0700
+++ b/src/hotspot/cpu/s390/interp_masm_s390.hpp	Mon Oct 30 17:14:39 2017 +0100
@@ -86,6 +86,8 @@
   void dispatch_next_noverify_oop(TosState state, int step = 0);
   void dispatch_via(TosState state, address* table);
 
+  void narrow(Register result, Register ret_type);
+
   // Jump to an invoked target.
   void prepare_to_jump_from_interpreted(Register method);
   void jump_from_interpreted(Register method, Register temp);

--- a/src/hotspot/cpu/s390/templateInterpreterGenerator_s390.cpp	Sun Oct 29 18:13:18 2017 -0700
+++ b/src/hotspot/cpu/s390/templateInterpreterGenerator_s390.cpp	Mon Oct 30 17:14:39 2017 +0100
@@ -2377,6 +2377,12 @@
   __ store_const(Address(RjvmtiState, JvmtiThreadState::earlyret_state_offset()),
                  JvmtiThreadState::earlyret_inactive, 4, 4, Z_R0_scratch);
 
+  if (state == itos) {
+    // Narrow result if state is itos but result type is smaller.
+    // Need to narrow in the return bytecode rather than in generate_return_entry
+    // since compiled code callers expect the result to already be narrowed.
+    __ narrow(Z_tos, Z_tmp_1); /* fall through */
+  }
   __ remove_activation(state,
                        Z_tmp_1, // retaddr
                        false,   // throw_monitor_exception

--- a/src/hotspot/cpu/s390/templateTable_s390.cpp	Sun Oct 29 18:13:18 2017 -0700
+++ b/src/hotspot/cpu/s390/templateTable_s390.cpp	Mon Oct 30 17:14:39 2017 +0100
@@ -1174,8 +1174,20 @@
   __ pop_i(Z_ARG3);
   __ pop_ptr(Z_tmp_2);
   // Z_tos   : value
-  // Z_ARG3 : index
+  // Z_ARG3  : index
   // Z_tmp_2 : array
+
+  // Need to check whether array is boolean or byte
+  // since both types share the bastore bytecode.
+  __ load_klass(Z_tmp_1, Z_tmp_2);
+  __ z_llgf(Z_tmp_1, Address(Z_tmp_1, Klass::layout_helper_offset()));
+  __ z_tmll(Z_tmp_1, Klass::layout_helper_boolean_diffbit());
+  Label L_skip;
+  __ z_bfalse(L_skip);
+  // if it is a T_BOOLEAN array, mask the stored value to 0/1
+  __ z_nilf(Z_tos, 0x1);
+  __ bind(L_skip);
+
   // No index shift necessary - pass 0.
   index_check(Z_tmp_2, Z_ARG3, 0); // Prefer index in Z_ARG3.
   __ z_stc(Z_tos,
@@ -2321,6 +2333,13 @@
     __ bind(skip_register_finalizer);
   }
 
+  if (state == itos) {
+    // Narrow result if state is itos but result type is smaller.
+    // Need to narrow in the return bytecode rather than in generate_return_entry
+    // since compiled code callers expect the result to already be narrowed.
+    __ narrow(Z_tos, Z_tmp_1); /* fall through */
+  }
+
   __ remove_activation(state, Z_R14);
   __ z_br(Z_R14);
 }