1 /* 2 * Copyright 1998-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 // The Rewriter adds caches to the constant pool and rewrites bytecode indices 26 // pointing into the constant pool for better interpreter performance. 27 28 class Rewriter: public StackObj { 29 private: 30 instanceKlassHandle _klass; 31 constantPoolHandle _pool; 32 objArrayHandle _methods; 33 intArray _cp_map; 34 intStack _cp_cache_map; 35 36 void init_cp_map(int length) { 37 _cp_map.initialize(length, -1); 38 // Choose an initial value large enough that we don't get frequent 39 // calls to grow(). 40 _cp_cache_map.initialize(length / 2); 41 } 42 int cp_entry_to_cp_cache(int i) { assert(has_cp_cache(i), "oob"); return _cp_map[i]; } 43 bool has_cp_cache(int i) { return (uint)i < (uint)_cp_map.length() && _cp_map[i] >= 0; } 44 int maybe_add_cp_cache_entry(int i) { return has_cp_cache(i) ? _cp_map[i] : add_cp_cache_entry(i); } 45 int add_cp_cache_entry(int cp_index) { 46 assert((cp_index & _secondary_entry_tag) == 0, "bad tag"); 47 assert(_cp_map[cp_index] == -1, "not twice on same cp_index"); 48 int cache_index = _cp_cache_map.append(cp_index); 49 _cp_map.at_put(cp_index, cache_index); 50 assert(cp_entry_to_cp_cache(cp_index) == cache_index, ""); 51 return cache_index; 52 } 53 int add_secondary_cp_cache_entry(int main_cpc_entry) { 54 assert(main_cpc_entry < _cp_cache_map.length(), "must be earlier CP cache entry"); 55 int cache_index = _cp_cache_map.append(main_cpc_entry | _secondary_entry_tag); 56 return cache_index; 57 } 58 59 // All the work goes in here: 60 Rewriter(instanceKlassHandle klass, TRAPS); 61 62 void compute_index_maps(); 63 void make_constant_pool_cache(TRAPS); 64 void scan_method(methodOop m); 65 methodHandle rewrite_jsrs(methodHandle m, TRAPS); 66 void rewrite_Object_init(methodHandle m, TRAPS); 67 int rewrite_member_reference(address bcp, int offset); 68 void rewrite_invokedynamic(address bcp, int offset, int cp_index); 69 70 public: 71 // Driver routine: 72 static void rewrite(instanceKlassHandle klass, TRAPS); 73 74 enum { 75 _secondary_entry_tag = nth_bit(30) 76 }; 77 };