1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_CI_CIVALUEKLASS_HPP
  26 #define SHARE_VM_CI_CIVALUEKLASS_HPP
  27 
  28 #include "ci/ciConstantPoolCache.hpp"
  29 #include "ci/ciEnv.hpp"
  30 #include "ci/ciFlags.hpp"
  31 #include "ci/ciInstanceKlass.hpp"
  32 #include "ci/ciSymbol.hpp"
  33 #include "oops/valueKlass.hpp"
  34 
  35 // ciValueKlass
  36 //
  37 // Specialized ciInstanceKlass for value types.
  38 class ciValueKlass : public ciInstanceKlass {
  39   CI_PACKAGE_ACCESS
  40 
  41 private:
  42   // Index fields of a value type, indeces range from 0 to the number of fields of the
  43   // value type - 1.
  44   // For each index constructed, _field_index_map records the field's index
  45   // in InstanceKlass::_fields (i.e., _field_index_map records the value returned by
  46   // fieldDescriptor::index() for each field).
  47   GrowableArray<int>* _field_index_map;
  48 
  49 protected:
  50   ciValueKlass(Klass* h_k) : ciInstanceKlass(h_k), _field_index_map(NULL) {
  51     assert(is_final(), "ValueKlass must be final");
  52   };
  53 
  54   const char* type_string() { return "ciValueKlass"; }
  55   int compute_field_index_map();
  56 
  57   ValueKlass* get_valueKlass() const {
  58     return ValueKlass::cast(get_Klass());
  59   }
  60 
  61 public:
  62   bool      is_valuetype() const { return true; }
  63   bool      flatten_array() const;
  64   bool      contains_oops() const;
  65 
  66   // Value type fields
  67   int       field_count();
  68   int       field_size();
  69   int       flattened_field_count() {
  70     return nof_nonstatic_fields();
  71   }
  72   int       field_index_by_offset(int offset);
  73   int       field_offset_by_index(int index);
  74   ciType*   field_type_by_index(int index);
  75   int       first_field_offset() const;
  76 
  77   int value_arg_slots();
  78 
  79   // Can a value type instance of this type be returned as multiple
  80   // returned values?
  81   bool can_be_returned_as_fields() const {
  82     return this != ciEnv::current()->___Value_klass() && get_valueKlass()->return_regs() != NULL;
  83   }
  84 };
  85 
  86 #endif // SHARE_VM_CI_CIVALUEKLASS_HPP