Wed, 17 Sep 2008 12:59:52 -0700
6384206: Phis which are later unneeded are impairing our ability to inline based on static types
Reviewed-by: rasbold, jrose
1 /*
2 * Copyright 2005-2008 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 */
25 define_array(ciObjectArray, ciObject*);
26 define_stack(ciObjectList, ciObjectArray);
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.
32 class ciMethodBlocks;
33 class ciBlock;
35 class 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;
43 intStack _stack;
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;
52 bool _return_local;
53 bool _return_allocated;
54 bool _allocated_escapes;
55 bool _unknown_modified;
57 ciObjectList _dependencies;
59 ciMethodBlocks *_methodBlocks;
61 BCEscapeAnalyzer* _parent;
62 int _level;
64 class ArgumentMap;
65 class StateInfo;
67 // helper functions
68 bool is_argument(int i) { return i >= 0 && i < _arg_size; }
70 void raw_push(int i) { _stack.push(i); }
71 int raw_pop() { return _stack.is_empty() ? -1 : _stack.pop(); }
72 void apush(int i) { raw_push(i); }
73 void spush() { raw_push(-1); }
74 void lpush() { spush(); spush(); }
75 int apop() { return raw_pop(); }
76 void spop() { assert(_stack.is_empty() || _stack.top() == -1, ""); raw_pop(); }
77 void lpop() { spop(); spop(); }
79 void set_returned(ArgumentMap vars);
80 bool is_argument(ArgumentMap vars);
81 bool is_arg_stack(ArgumentMap vars);
82 void clear_bits(ArgumentMap vars, BitMap &bs);
83 void set_method_escape(ArgumentMap vars);
84 void set_global_escape(ArgumentMap vars);
85 void set_dirty(ArgumentMap vars);
86 void set_modified(ArgumentMap vars, int offs, int size);
88 bool is_recursive_call(ciMethod* callee);
89 void add_dependence(ciKlass *klass, ciMethod *meth);
90 void propagate_dependencies(ciMethod *meth);
91 void invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder);
93 void iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors);
94 void iterate_blocks(Arena *);
95 void merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state);
97 // analysis
98 void initialize();
99 void clear_escape_info();
100 void compute_escape_info();
101 vmIntrinsics::ID known_intrinsic();
102 bool compute_escape_for_intrinsic(vmIntrinsics::ID iid);
103 bool do_analysis();
105 void read_escape_info();
107 bool contains(uint arg_set1, uint arg_set2);
109 public:
110 BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent = NULL);
112 // accessors
113 ciMethod* method() const { return _method; }
114 ciMethodData* methodData() const { return _methodData; }
115 BCEscapeAnalyzer* parent() const { return _parent; }
116 int level() const { return _level; }
117 ciObjectList* dependencies() { return &_dependencies; }
118 bool has_dependencies() const { return !_dependencies.is_empty(); }
120 // retrieval of interprocedural escape information
122 // The given argument does not escape the callee.
123 bool is_arg_local(int i) const {
124 return !_conservative && _arg_local.at(i);
125 }
127 // The given argument escapes the callee, but does not become globally
128 // reachable.
129 bool is_arg_stack(int i) const {
130 return !_conservative && _arg_stack.at(i);
131 }
133 // The given argument does not escape globally, and may be returned.
134 bool is_arg_returned(int i) const {
135 return !_conservative && _arg_returned.at(i); }
137 // True iff only input arguments are returned.
138 bool is_return_local() const {
139 return !_conservative && _return_local;
140 }
142 // True iff only newly allocated unescaped objects are returned.
143 bool is_return_allocated() const {
144 return !_conservative && _return_allocated && !_allocated_escapes;
145 }
147 // Tracking of argument modification
149 enum {OFFSET_ANY = -1};
150 bool is_arg_modified(int arg, int offset, int size_in_bytes);
151 void set_arg_modified(int arg, int offset, int size_in_bytes);
152 bool has_non_arg_side_affects() { return _unknown_modified; }
154 // Copy dependencies from this analysis into "deps"
155 void copy_dependencies(Dependencies *deps);
157 #ifndef PRODUCT
158 // dump escape information
159 void dump();
160 #endif
161 };