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. 22 * 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 35class Rewriter: public StackObj { 36 private: 37 instanceKlassHandle _klass; 38 constantPoolHandle _pool; 39 Array<Method*>* _methods; 40 GrowableArray<int> _cp_map; 41 GrowableArray<int> _cp_cache_map; // for Methodref, Fieldref, 42 // InterfaceMethodref and InvokeDynamic 43 GrowableArray<int> _reference_map; // maps from cp index to resolved_refs index (or -1) 44 GrowableArray<int> _resolved_references_map; // for strings, methodHandle, methodType 45 GrowableArray<int> _invokedynamic_references_map; // for invokedynamic resolved refs 46 GrowableArray<int> _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 GrowableArray<int> _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.trunc_to(0); 62 _cp_map.at_grow(length, -1); 63 64 _cp_cache_map.trunc_to(0); 65 // Also cache resolved objects, in another different cache. 66 _reference_map.trunc_to(0); 67 _reference_map.at_grow(length, -1); 68 69 _method_handle_invokers.trunc_to(0); 70 _resolved_references_map.trunc_to(0); 71 _invokedynamic_references_map.trunc_to(0); 72 _resolved_reference_limit = -1; 73 _first_iteration_cp_cache_limit = -1; 74 75 // invokedynamic specific fields 76 _invokedynamic_cp_cache_map.trunc_to(0); 77 _patch_invokedynamic_bcps = new GrowableArray<address>(length / 4); 78 _patch_invokedynamic_refs = new GrowableArray<int>(length / 4); 79 } 80 81 int _first_iteration_cp_cache_limit; 82 void record_map_limits() { 83 // Record initial size of the two arrays generated for the CP cache 84 // relative to walking the constant pool. 85 _first_iteration_cp_cache_limit = _cp_cache_map.length(); 86 _resolved_reference_limit = _resolved_references_map.length(); 87 } 88 89 int cp_cache_delta() { 90 // How many cp cache entries were added since recording map limits after 91 // cp cache initialization? 92 assert(_first_iteration_cp_cache_limit != -1, "only valid after first iteration"); 93 return _cp_cache_map.length() - _first_iteration_cp_cache_limit; 94 } 95 96 int cp_entry_to_cp_cache(int i) { assert(has_cp_cache(i), "oob"); return _cp_map.at(i); } 97 bool has_cp_cache(int i) { return (uint) i < (uint) _cp_map.length() && _cp_map.at(i) >= 0; } 98 99 int add_map_entry(int cp_index, GrowableArray<int>* cp_map, GrowableArray<int>* cp_cache_map) { 100 assert(cp_map->at(cp_index) == -1, "not twice on same cp_index"); 101 int cache_index = cp_cache_map->append(cp_index); 102 cp_map->at_put(cp_index, cache_index); 103 return cache_index; 104 } 105 106 int add_cp_cache_entry(int cp_index) { 107 assert(_pool->tag_at(cp_index).value() != JVM_CONSTANT_InvokeDynamic, "use indy version"); 108 assert(_first_iteration_cp_cache_limit == -1, "do not add cache entries after first iteration"); 109 int cache_index = add_map_entry(cp_index, &_cp_map, &_cp_cache_map); 110 assert(cp_entry_to_cp_cache(cp_index) == cache_index, ""); 111 assert(cp_cache_entry_pool_index(cache_index) == cp_index, ""); 112 return cache_index; 113 } 114 115 int add_invokedynamic_cp_cache_entry(int cp_index) { 116 assert(_pool->tag_at(cp_index).value() == JVM_CONSTANT_InvokeDynamic, "use non-indy version"); 117 assert(_first_iteration_cp_cache_limit >= 0, "add indy cache entries after first iteration"); 118 // add to the invokedynamic index map. 119 int cache_index = _invokedynamic_cp_cache_map.append(cp_index); 120 // do not update _cp_map, since the mapping is one-to-many 121 assert(invokedynamic_cp_cache_entry_pool_index(cache_index) == cp_index, ""); 122 // this index starts at one but in the bytecode it's appended to the end. 123 return cache_index + _first_iteration_cp_cache_limit; 124 } 125 126 int invokedynamic_cp_cache_entry_pool_index(int cache_index) { 127 int cp_index = _invokedynamic_cp_cache_map.at(cache_index); 128 return cp_index; 129 } 130 131 // add a new CP cache entry beyond the normal cache for the special case of 132 // invokespecial with InterfaceMethodref as cpool operand. 133 int add_invokespecial_cp_cache_entry(int cp_index) { 134 assert(_first_iteration_cp_cache_limit >= 0, "add these special cache entries after first iteration"); 135 // Don't add InterfaceMethodref if it already exists at the end. 136 for (int i = _first_iteration_cp_cache_limit; i < _cp_cache_map.length(); i++) { 137 if (cp_cache_entry_pool_index(i) == cp_index) { 138 return i; 139 } 140 } 141 int cache_index = _cp_cache_map.append(cp_index); 142 assert(cache_index >= _first_iteration_cp_cache_limit, ""); 143 // do not update _cp_map, since the mapping is one-to-many 144 assert(cp_cache_entry_pool_index(cache_index) == cp_index, ""); 145 return cache_index; 146 } 147 148 int cp_entry_to_resolved_references(int cp_index) const { 149 assert(has_entry_in_resolved_references(cp_index), "oob"); 150 return _reference_map.at(cp_index); 151 } 152 bool has_entry_in_resolved_references(int cp_index) const { 153 return (uint) cp_index < (uint) _reference_map.length() && _reference_map.at(cp_index) >= 0; 154 } 155 156 // add a new entry to the resolved_references map 157 int add_resolved_references_entry(int cp_index) { 158 int ref_index = add_map_entry(cp_index, &_reference_map, &_resolved_references_map); 159 assert(cp_entry_to_resolved_references(cp_index) == ref_index, ""); 160 return ref_index; 161 } 162 163 // add a new entries to the resolved_references map (for invokedynamic and invokehandle only) 164 int add_invokedynamic_resolved_references_entries(int cp_index, int cache_index) { 165 assert(_resolved_reference_limit >= 0, "must add indy refs after first iteration"); 166 int ref_index = -1; 167 for (int entry = 0; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) { 168 const int index = _resolved_references_map.append(cp_index); // many-to-one 169 assert(index >= _resolved_reference_limit, ""); 170 if (entry == 0) { 171 ref_index = index; 172 } 173 assert((index - entry) == ref_index, "entries must be consecutive"); 174 _invokedynamic_references_map.at_put_grow(index, cache_index, -1); 175 } 176 return ref_index; 177 } 178 179 int resolved_references_entry_to_pool_index(int ref_index) { 180 int cp_index = _resolved_references_map.at(ref_index); 181 return cp_index; 182 } 183 184 // Access the contents of _cp_cache_map to determine CP cache layout. 185 int cp_cache_entry_pool_index(int cache_index) { 186 int cp_index = _cp_cache_map.at(cache_index); 187 return cp_index; 188 } 189 190 // All the work goes in here: 191 Rewriter(instanceKlassHandle klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS); 192 193 void compute_index_maps(); 194 void make_constant_pool_cache(TRAPS); 195 void scan_method(Method* m, bool reverse, bool* invokespecial_error); 196 void rewrite_Object_init(methodHandle m, TRAPS); 197 void rewrite_member_reference(address bcp, int offset, bool reverse); 198 void maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse); 199 void rewrite_invokedynamic(address bcp, int offset, bool reverse); 200 void maybe_rewrite_ldc(address bcp, int offset, bool is_wide, bool reverse); 201 void rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error); 202 203 void patch_invokedynamic_bytecodes(); 204 205 // Do all the work. 206 void rewrite_bytecodes(TRAPS); 207 208 // Revert bytecodes in case of an exception. 209 void restore_bytecodes(); 210 211 static methodHandle rewrite_jsrs(methodHandle m, TRAPS); 212 public: 213 // Driver routine: 214 static void rewrite(instanceKlassHandle klass, TRAPS); 215}; 216 217#endif // SHARE_VM_INTERPRETER_REWRITER_HPP 218