1 /*
2 * Copyright (c) 1998, 2015, 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.
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23 */
24
25 #ifndef SHARE_VM_INTERPRETER_REWRITER_HPP
26 #define SHARE_VM_INTERPRETER_REWRITER_HPP
27
28 #include "memory/allocation.hpp"
29 #include "runtime/handles.inline.hpp"
30 #include "utilities/growableArray.hpp"
31
32 // The Rewriter adds caches to the constant pool and rewrites bytecode indices
33 // pointing into the constant pool for better interpreter performance.
34
35 class Rewriter: public StackObj {
36 private:
37 instanceKlassHandle _klass;
38 constantPoolHandle _pool;
39 Array<Method*>* _methods;
40 intArray _cp_map;
41 intStack _cp_cache_map; // for Methodref, Fieldref,
42 // InterfaceMethodref and InvokeDynamic
43 intArray _reference_map; // maps from cp index to resolved_refs index (or -1)
44 intStack _resolved_references_map; // for strings, methodHandle, methodType
45 intStack _invokedynamic_references_map; // for invokedynamic resolved refs
46 intArray _method_handle_invokers;
47 int _resolved_reference_limit;
48
49 // For mapping invokedynamic bytecodes, which are discovered during method
50 // scanning. The invokedynamic entries are added at the end of the cpCache.
51 // If there are any invokespecial/InterfaceMethodref special case bytecodes,
52 // these entries are added before invokedynamic entries so that the
53 // invokespecial bytecode 16 bit index doesn't overflow.
54 intStack _invokedynamic_cp_cache_map;
55
56 // For patching.
57 GrowableArray<address>* _patch_invokedynamic_bcps;
58 GrowableArray<int>* _patch_invokedynamic_refs;
59
60 void init_maps(int length) {
61 _cp_map.initialize(length, -1);
62 // Choose an initial value large enough that we don't get frequent
63 // calls to grow().
64 _cp_cache_map.initialize(length/2);
65 // Also cache resolved objects, in another different cache.
66 _reference_map.initialize(length, -1);
67 _resolved_references_map.initialize(length/2);
68 _invokedynamic_references_map.initialize(length/2);
69 _resolved_reference_limit = -1;
70 _first_iteration_cp_cache_limit = -1;
71
72 // invokedynamic specific fields
73 _invokedynamic_cp_cache_map.initialize(length/4);
74 _patch_invokedynamic_bcps = new GrowableArray<address>(length/4);
75 _patch_invokedynamic_refs = new GrowableArray<int>(length/4);
76 }
77
78 int _first_iteration_cp_cache_limit;
79 void record_map_limits() {
80 // Record initial size of the two arrays generated for the CP cache
81 // relative to walking the constant pool.
82 _first_iteration_cp_cache_limit = _cp_cache_map.length();
83 _resolved_reference_limit = _resolved_references_map.length();
84 }
85
86 int cp_cache_delta() {
87 // How many cp cache entries were added since recording map limits after
88 // cp cache initialization?
89 assert(_first_iteration_cp_cache_limit != -1, "only valid after first iteration");
90 return _cp_cache_map.length() - _first_iteration_cp_cache_limit;
91 }
92
93 int cp_entry_to_cp_cache(int i) { assert(has_cp_cache(i), "oob"); return _cp_map[i]; }
94 bool has_cp_cache(int i) { return (uint)i < (uint)_cp_map.length() && _cp_map[i] >= 0; }
95
96 int add_map_entry(int cp_index, intArray* cp_map, intStack* cp_cache_map) {
97 assert(cp_map->at(cp_index) == -1, "not twice on same cp_index");
98 int cache_index = cp_cache_map->append(cp_index);
99 cp_map->at_put(cp_index, cache_index);
100 return cache_index;
101 }
102
103 int add_cp_cache_entry(int cp_index) {
104 assert(_pool->tag_at(cp_index).value() != JVM_CONSTANT_InvokeDynamic, "use indy version");
105 assert(_first_iteration_cp_cache_limit == -1, "do not add cache entries after first iteration");
106 int cache_index = add_map_entry(cp_index, &_cp_map, &_cp_cache_map);
107 assert(cp_entry_to_cp_cache(cp_index) == cache_index, "");
108 assert(cp_cache_entry_pool_index(cache_index) == cp_index, "");
109 return cache_index;
110 }
111
112 int add_invokedynamic_cp_cache_entry(int cp_index) {
113 assert(_pool->tag_at(cp_index).value() == JVM_CONSTANT_InvokeDynamic, "use non-indy version");
114 assert(_first_iteration_cp_cache_limit >= 0, "add indy cache entries after first iteration");
115 // add to the invokedynamic index map.
116 int cache_index = _invokedynamic_cp_cache_map.append(cp_index);
117 // do not update _cp_map, since the mapping is one-to-many
118 assert(invokedynamic_cp_cache_entry_pool_index(cache_index) == cp_index, "");
119 // this index starts at one but in the bytecode it's appended to the end.
120 return cache_index + _first_iteration_cp_cache_limit;
121 }
122
123 int invokedynamic_cp_cache_entry_pool_index(int cache_index) {
124 int cp_index = _invokedynamic_cp_cache_map[cache_index];
125 return cp_index;
126 }
127
128 // add a new CP cache entry beyond the normal cache for the special case of
129 // invokespecial with InterfaceMethodref as cpool operand.
130 int add_invokespecial_cp_cache_entry(int cp_index) {
131 assert(_first_iteration_cp_cache_limit >= 0, "add these special cache entries after first iteration");
132 // Don't add InterfaceMethodref if it already exists at the end.
133 for (int i = _first_iteration_cp_cache_limit; i < _cp_cache_map.length(); i++) {
134 if (cp_cache_entry_pool_index(i) == cp_index) {
135 return i;
136 }
137 }
138 int cache_index = _cp_cache_map.append(cp_index);
139 assert(cache_index >= _first_iteration_cp_cache_limit, "");
140 // do not update _cp_map, since the mapping is one-to-many
141 assert(cp_cache_entry_pool_index(cache_index) == cp_index, "");
142 return cache_index;
143 }
144
145 int cp_entry_to_resolved_references(int cp_index) const {
146 assert(has_entry_in_resolved_references(cp_index), "oob");
147 return _reference_map[cp_index];
148 }
149 bool has_entry_in_resolved_references(int cp_index) const {
150 return (uint)cp_index < (uint)_reference_map.length() && _reference_map[cp_index] >= 0;
151 }
152
153 // add a new entry to the resolved_references map
154 int add_resolved_references_entry(int cp_index) {
155 int ref_index = add_map_entry(cp_index, &_reference_map, &_resolved_references_map);
156 assert(cp_entry_to_resolved_references(cp_index) == ref_index, "");
157 return ref_index;
158 }
159
160 // add a new entries to the resolved_references map (for invokedynamic and invokehandle only)
161 int add_invokedynamic_resolved_references_entries(int cp_index, int cache_index) {
162 assert(_resolved_reference_limit >= 0, "must add indy refs after first iteration");
163 int ref_index = -1;
164 for (int entry = 0; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
165 const int index = _resolved_references_map.append(cp_index); // many-to-one
166 assert(index >= _resolved_reference_limit, "");
167 if (entry == 0) {
168 ref_index = index;
169 }
170 assert((index - entry) == ref_index, "entries must be consecutive");
171 _invokedynamic_references_map.at_put_grow(index, cache_index, -1);
172 }
173 return ref_index;
174 }
175
176 int resolved_references_entry_to_pool_index(int ref_index) {
177 int cp_index = _resolved_references_map[ref_index];
178 return cp_index;
179 }
180
181 // Access the contents of _cp_cache_map to determine CP cache layout.
182 int cp_cache_entry_pool_index(int cache_index) {
183 int cp_index = _cp_cache_map[cache_index];
184 return cp_index;
185 }
186
187 // All the work goes in here:
188 Rewriter(instanceKlassHandle klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS);
189
190 void compute_index_maps();
191 void make_constant_pool_cache(TRAPS);
192 void scan_method(Method* m, bool reverse, bool* invokespecial_error);
193 void rewrite_Object_init(methodHandle m, TRAPS);
194 void rewrite_member_reference(address bcp, int offset, bool reverse);
195 void maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse);
196 void rewrite_invokedynamic(address bcp, int offset, bool reverse);
197 void maybe_rewrite_ldc(address bcp, int offset, bool is_wide, bool reverse);
198 void rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error);
199
200 void patch_invokedynamic_bytecodes();
201
202 // Do all the work.
203 void rewrite_bytecodes(TRAPS);
204
205 // Revert bytecodes in case of an exception.
206 void restore_bytecodes();
207
208 static methodHandle rewrite_jsrs(methodHandle m, TRAPS);
209 public:
210 // Driver routine:
211 static void rewrite(instanceKlassHandle klass, TRAPS);
212 };
213
214 #endif // SHARE_VM_INTERPRETER_REWRITER_HPP