1/*
2 * Copyright (c) 2005, 2019, 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
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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.
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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
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23 */
24
25#ifndef SHARE_CI_BCESCAPEANALYZER_HPP
26#define SHARE_CI_BCESCAPEANALYZER_HPP
27
28#ifdef COMPILER2
29#include "ci/ciObject.hpp"
30#include "ci/ciMethod.hpp"
31#include "ci/ciMethodData.hpp"
32#include "code/dependencies.hpp"
33#include "libadt/vectset.hpp"
34#include "memory/allocation.hpp"
35#include "utilities/growableArray.hpp"
36#endif
37
38// This class implements a fast, conservative analysis of effect of methods
39// on the escape state of their arguments. The analysis is at the bytecode
40// level.
41
42class ciMethodBlocks;
43class ciBlock;
44
45class BCEscapeAnalyzer : public ResourceObj {
46 private:
47 Arena* _arena; // ciEnv arena
48
49 bool _conservative; // If true, return maximally
50 // conservative results.
51 ciMethod* _method;
52 ciMethodData* _methodData;
53 int _arg_size;
54 VectorSet _arg_local;
55 VectorSet _arg_stack;
56 VectorSet _arg_returned;
57 VectorSet _dirty;
58 enum{ ARG_OFFSET_MAX = 31};
59 uint *_arg_modified;
60
61 bool _return_local;
62 bool _return_allocated;
63 bool _allocated_escapes;
64 bool _unknown_modified;
65
66 GrowableArray<ciMetadata *> _dependencies;
67
68 ciMethodBlocks *_methodBlocks;
69
70 BCEscapeAnalyzer* _parent;
71 int _level;
72
73 public:
74 class ArgumentMap;
75 class StateInfo;
76
77 private:
78 // helper functions
79 bool is_argument(int i) { return i >= 0 && i < _arg_size; }
80 void set_returned(ArgumentMap vars);
81 bool is_argument(ArgumentMap vars);
82 bool is_arg_stack(ArgumentMap vars);
83 bool returns_all(ArgumentMap vars);
84 void clear_bits(ArgumentMap vars, VectorSet &bs);
85 void set_method_escape(ArgumentMap vars);
86 void set_global_escape(ArgumentMap vars, bool merge = false);
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 void compute_escape_for_intrinsic(vmIntrinsics::ID iid);
105 void 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 GrowableArray<ciMetadata *>* 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.test(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.test(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.test(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
165#endif // SHARE_CI_BCESCAPEANALYZER_HPP
166