bcEscapeAnalyzer.hpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 2005, 2008, 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 25define_array(ciObjectArray, ciObject*); 26define_stack(ciObjectList, ciObjectArray); 27 28// This class implements a fast, conservative analysis of effect of methods 29// on the escape state of their arguments. The analysis is at the bytecode 30// level. 31 32class ciMethodBlocks; 33class ciBlock; 34 35class BCEscapeAnalyzer : public ResourceObj { 36 private: 37 bool _conservative; // If true, return maximally 38 // conservative results. 39 ciMethod* _method; 40 ciMethodData* _methodData; 41 int _arg_size; 42 43 intStack _stack; 44 45 BitMap _arg_local; 46 BitMap _arg_stack; 47 BitMap _arg_returned; 48 BitMap _dirty; 49 enum{ ARG_OFFSET_MAX = 31}; 50 uint *_arg_modified; 51 52 bool _return_local; 53 bool _return_allocated; 54 bool _allocated_escapes; 55 bool _unknown_modified; 56 57 ciObjectList _dependencies; 58 59 ciMethodBlocks *_methodBlocks; 60 61 BCEscapeAnalyzer* _parent; 62 int _level; 63 64 public: 65 class ArgumentMap; 66 class StateInfo; 67 68 private: 69 // helper functions 70 bool is_argument(int i) { return i >= 0 && i < _arg_size; } 71 72 void raw_push(int i) { _stack.push(i); } 73 int raw_pop() { return _stack.is_empty() ? -1 : _stack.pop(); } 74 void apush(int i) { raw_push(i); } 75 void spush() { raw_push(-1); } 76 void lpush() { spush(); spush(); } 77 int apop() { return raw_pop(); } 78 void spop() { assert(_stack.is_empty() || _stack.top() == -1, ""); raw_pop(); } 79 void lpop() { spop(); spop(); } 80 81 void set_returned(ArgumentMap vars); 82 bool is_argument(ArgumentMap vars); 83 bool is_arg_stack(ArgumentMap vars); 84 void clear_bits(ArgumentMap vars, BitMap &bs); 85 void set_method_escape(ArgumentMap vars); 86 void set_global_escape(ArgumentMap vars); 87 void set_dirty(ArgumentMap vars); 88 void set_modified(ArgumentMap vars, int offs, int size); 89 90 bool is_recursive_call(ciMethod* callee); 91 void add_dependence(ciKlass *klass, ciMethod *meth); 92 void propagate_dependencies(ciMethod *meth); 93 void invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder); 94 95 void iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors); 96 void iterate_blocks(Arena *); 97 void merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state); 98 99 // analysis 100 void initialize(); 101 void clear_escape_info(); 102 void compute_escape_info(); 103 vmIntrinsics::ID known_intrinsic(); 104 bool compute_escape_for_intrinsic(vmIntrinsics::ID iid); 105 bool do_analysis(); 106 107 void read_escape_info(); 108 109 bool contains(uint arg_set1, uint arg_set2); 110 111 public: 112 BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent = NULL); 113 114 // accessors 115 ciMethod* method() const { return _method; } 116 ciMethodData* methodData() const { return _methodData; } 117 BCEscapeAnalyzer* parent() const { return _parent; } 118 int level() const { return _level; } 119 ciObjectList* dependencies() { return &_dependencies; } 120 bool has_dependencies() const { return !_dependencies.is_empty(); } 121 122 // retrieval of interprocedural escape information 123 124 // The given argument does not escape the callee. 125 bool is_arg_local(int i) const { 126 return !_conservative && _arg_local.at(i); 127 } 128 129 // The given argument escapes the callee, but does not become globally 130 // reachable. 131 bool is_arg_stack(int i) const { 132 return !_conservative && _arg_stack.at(i); 133 } 134 135 // The given argument does not escape globally, and may be returned. 136 bool is_arg_returned(int i) const { 137 return !_conservative && _arg_returned.at(i); } 138 139 // True iff only input arguments are returned. 140 bool is_return_local() const { 141 return !_conservative && _return_local; 142 } 143 144 // True iff only newly allocated unescaped objects are returned. 145 bool is_return_allocated() const { 146 return !_conservative && _return_allocated && !_allocated_escapes; 147 } 148 149 // Tracking of argument modification 150 151 enum {OFFSET_ANY = -1}; 152 bool is_arg_modified(int arg, int offset, int size_in_bytes); 153 void set_arg_modified(int arg, int offset, int size_in_bytes); 154 bool has_non_arg_side_affects() { return _unknown_modified; } 155 156 // Copy dependencies from this analysis into "deps" 157 void copy_dependencies(Dependencies *deps); 158 159#ifndef PRODUCT 160 // dump escape information 161 void dump(); 162#endif 163}; 164