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 #include "precompiled.hpp"
26 #include "ci/ciField.hpp"
27 #include "ci/ciValueKlass.hpp"
28 #include "oops/fieldStreams.hpp"
29 #include "oops/valueKlass.hpp"
30
31 int ciValueKlass::compute_field_index_map() {
32 assert(is_loaded(), "value class must be loaded to compute mapping of field indeces");
33
34 if (_field_index_map != NULL) {
35 return _field_index_map->length();
36 }
37
38 Arena* arena = CURRENT_ENV->arena();
39 guarantee(has_nonstatic_fields(), "value types without fields currently not supported");
40
41 // FIXME: Once it is possible to construct class hierarchies with value types.
42 assert(!super()->has_nonstatic_fields(), "a value type must not inherit fields from its superclass");
43
44 _field_index_map = new (arena) GrowableArray<int>(arena, nof_declared_nonstatic_fields(), 0, 0);
45 ValueKlass* vklass = ValueKlass::cast(get_Klass());
46 for (JavaFieldStream fs(vklass); !fs.done(); fs.next()) {
47 if (fs.access_flags().is_static()) {
48 continue;
49 }
50 _field_index_map->append(fs.field_descriptor().index());
51 }
52 return _field_index_map->length();
53 }
54
55 // Number of value type fields
56 int ciValueKlass::field_count() {
57 if (this == ciEnv::current()->___Value_klass()) {
58 return 0;
59 }
60 if (_field_index_map == NULL) {
61 return compute_field_index_map();
62 } else {
63 return _field_index_map->length();
64 }
65 }
66
67 // Size of value type fields in words
68 int ciValueKlass::field_size() {
69 int size = 0;
70 for (int i = 0; i < field_count(); ++i) {
71 size += field_type_by_index(i)->size();
72 }
73 return size;
74 }
75
76 // Returns the index of the field with the given offset. If the field at 'offset'
77 // belongs to a flattened value type field, return the index of the field
78 // in the flattened value type.
79 int ciValueKlass::field_index_by_offset(int offset) {
80 assert(contains_field_offset(offset), "invalid field offset");
81 int best_offset = 0;
82 int best_index = -1;
83 // Search the field with the given offset
84 for (int i = 0; i < field_count(); ++i) {
85 int field_offset = field_offset_by_index(i);
86 if (field_offset == offset) {
87 // Exact match
88 return i;
89 } else if (field_offset < offset && field_offset > best_offset) {
90 // No exact match. Save the index of the field with the closest offset that
91 // is smaller than the given field offset. This index corresponds to the
92 // flattened value type field that holds the field we are looking for.
93 best_offset = field_offset;
94 best_index = i;
95 }
96 }
97 assert(best_index >= 0, "field not found");
98 assert(best_offset == offset || field_type_by_index(best_index)->is_valuetype(), "offset should match for non-VTs");
99 return best_index;
100 }
101
102 // Returns the field offset of the field with the given index
103 int ciValueKlass::field_offset_by_index(int index) {
104 if (_field_index_map == NULL) {
105 compute_field_index_map();
106 }
107 GUARDED_VM_ENTRY(
108 ValueKlass* vklass = ValueKlass::cast(get_Klass());
109 return vklass->field_offset(_field_index_map->at(index));
110 )
111 }
112
113 // Returns the field type of the field with the given index
114 ciType* ciValueKlass::field_type_by_index(int index) {
115 int offset = field_offset_by_index(index);
116 VM_ENTRY_MARK;
117 return get_field_type_by_offset(offset);
118 }
119
120 // Offset of the first field in the value type
121 int ciValueKlass::first_field_offset() const {
122 GUARDED_VM_ENTRY(
123 ValueKlass* vklass = ValueKlass::cast(get_Klass());
124 return vklass->first_field_offset();
125 )
126 }
127
128 bool ciValueKlass::flatten_array() const {
129 GUARDED_VM_ENTRY(
130 ValueKlass* vklass = ValueKlass::cast(get_Klass());
131 return vklass->flatten_array();
132 )
133 }
134
135 bool ciValueKlass::contains_oops() const {
136 GUARDED_VM_ENTRY(
137 ValueKlass* vklass = ValueKlass::cast(get_Klass());
138 return vklass->contains_oops();
139 )
140 }
141
142 // When passing a value type's fields as arguments, count the number
143 // of argument slots that are needed
144 int ciValueKlass::value_arg_slots() {
145 int slots = nof_nonstatic_fields();
146 for (int j = 0; j < nof_nonstatic_fields(); j++) {
147 ciField* f = nonstatic_field_at(j);
148 BasicType bt = f->type()->basic_type();
149 assert(bt != T_VALUETYPE, "embedded");
150 if (bt == T_LONG || bt == T_DOUBLE) {
151 slots++;
152 }
153 }
154 return slots;
155 }