src/hotspot/share/c1/c1_LIR.cpp

*** 1060,1084 ****
  
  void LIR_OpJavaCall::emit_code(LIR_Assembler* masm) {
    masm->emit_call(this);
  }
  
! bool LIR_OpJavaCall::maybe_return_as_fields() const {
    if (ValueTypeReturnedAsFields) {
      if (method()->signature()->returns_never_null()) {
        ciType* return_type = method()->return_type();
        if (return_type->is_valuetype()) {
          ciValueKlass* vk = return_type->as_value_klass();
          if (vk->can_be_returned_as_fields()) {
            return true;
          }
        }
      } else if (is_method_handle_invoke()) {
        BasicType bt = method()->return_type()->basic_type();
        if (bt == T_OBJECT || bt == T_VALUETYPE) {
          // A value type might be returned from the call but we don't know its
          // type.
          return true;
        }
      }
    }
    return false;
--- 1060,1095 ----
  
  void LIR_OpJavaCall::emit_code(LIR_Assembler* masm) {
    masm->emit_call(this);
  }
  
! bool LIR_OpJavaCall::maybe_return_as_fields(ciValueKlass** vk_ret) const {
    if (ValueTypeReturnedAsFields) {
      if (method()->signature()->returns_never_null()) {
        ciType* return_type = method()->return_type();
        if (return_type->is_valuetype()) {
          ciValueKlass* vk = return_type->as_value_klass();
          if (vk->can_be_returned_as_fields()) {
+           if (vk_ret != NULL) {
+             *vk_ret = vk;
+           }
            return true;
          }
        }
      } else if (is_method_handle_invoke()) {
        BasicType bt = method()->return_type()->basic_type();
        if (bt == T_OBJECT || bt == T_VALUETYPE) {
          // A value type might be returned from the call but we don't know its
+         // type. Either we get a buffered value (and nothing needs to be done)
+         // or one of the values being returned is the klass of the value type
+         // (RAX on x64, with LSB set to 1) and we need to allocate a value
+         // type instance of that type and initialize it with other values being
+         // returned (in other registers).
          // type.
+         if (vk_ret != NULL) {
+           *vk_ret = NULL;
+         }
          return true;
        }
      }
    }
    return false;