Mercurial > hg > truffle
comparison src/share/vm/opto/escape.hpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
---|---|
date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | 99269dbf4ba8 |
comparison
equal
deleted
inserted
replaced
-1:000000000000 | 0:a61af66fc99e |
---|---|
1 /* | |
2 * Copyright 2005-2006 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 // | |
26 // Adaptation for C2 of the escape analysis algorithm described in: | |
27 // | |
28 // [Choi99] Jong-Deok Shoi, Manish Gupta, Mauricio Seffano, Vugranam C. Sreedhar, | |
29 // Sam Midkiff, "Escape Analysis for Java", Procedings of ACM SIGPLAN | |
30 // OOPSLA Conference, November 1, 1999 | |
31 // | |
32 // The flow-insensitive analysis described in the paper has been implemented. | |
33 // | |
34 // The analysis requires construction of a "connection graph" (CG) for the method being | |
35 // analyzed. The nodes of the connection graph are: | |
36 // | |
37 // - Java objects (JO) | |
38 // - Local variables (LV) | |
39 // - Fields of an object (OF), these also include array elements | |
40 // | |
41 // The CG contains 3 types of edges: | |
42 // | |
43 // - PointsTo (-P>) {LV,OF} to JO | |
44 // - Deferred (-D>) from {LV, OF} to {LV, OF} | |
45 // - Field (-F>) from JO to OF | |
46 // | |
47 // The following utility functions is used by the algorithm: | |
48 // | |
49 // PointsTo(n) - n is any CG node, it returns the set of JO that n could | |
50 // point to. | |
51 // | |
52 // The algorithm describes how to construct the connection graph in the following 4 cases: | |
53 // | |
54 // Case Edges Created | |
55 // | |
56 // (1) p = new T() LV -P> JO | |
57 // (2) p = q LV -D> LV | |
58 // (3) p.f = q JO -F> OF, OF -D> LV | |
59 // (4) p = q.f JO -F> OF, LV -D> OF | |
60 // | |
61 // In all these cases, p and q are local variables. For static field references, we can | |
62 // construct a local variable containing a reference to the static memory. | |
63 // | |
64 // C2 does not have local variables. However for the purposes of constructing | |
65 // the connection graph, the following IR nodes are treated as local variables: | |
66 // Phi (pointer values) | |
67 // LoadP | |
68 // Proj (value returned from callnodes including allocations) | |
69 // CheckCastPP | |
70 // | |
71 // The LoadP, Proj and CheckCastPP behave like variables assigned to only once. Only | |
72 // a Phi can have multiple assignments. Each input to a Phi is treated | |
73 // as an assignment to it. | |
74 // | |
75 // The following note types are JavaObject: | |
76 // | |
77 // top() | |
78 // Allocate | |
79 // AllocateArray | |
80 // Parm (for incoming arguments) | |
81 // CreateEx | |
82 // ConP | |
83 // LoadKlass | |
84 // | |
85 // AddP nodes are fields. | |
86 // | |
87 // After building the graph, a pass is made over the nodes, deleting deferred | |
88 // nodes and copying the edges from the target of the deferred edge to the | |
89 // source. This results in a graph with no deferred edges, only: | |
90 // | |
91 // LV -P> JO | |
92 // OF -P> JO | |
93 // JO -F> OF | |
94 // | |
95 // Then, for each node which is GlobalEscape, anything it could point to | |
96 // is marked GlobalEscape. Finally, for any node marked ArgEscape, anything | |
97 // it could point to is marked ArgEscape. | |
98 // | |
99 | |
100 class Compile; | |
101 class Node; | |
102 class CallNode; | |
103 class PhiNode; | |
104 class PhaseTransform; | |
105 class Type; | |
106 class TypePtr; | |
107 class VectorSet; | |
108 | |
109 class PointsToNode { | |
110 friend class ConnectionGraph; | |
111 public: | |
112 typedef enum { | |
113 UnknownType = 0, | |
114 JavaObject = 1, | |
115 LocalVar = 2, | |
116 Field = 3 | |
117 } NodeType; | |
118 | |
119 typedef enum { | |
120 UnknownEscape = 0, | |
121 NoEscape = 1, | |
122 ArgEscape = 2, | |
123 GlobalEscape = 3 | |
124 } EscapeState; | |
125 | |
126 typedef enum { | |
127 UnknownEdge = 0, | |
128 PointsToEdge = 1, | |
129 DeferredEdge = 2, | |
130 FieldEdge = 3 | |
131 } EdgeType; | |
132 | |
133 private: | |
134 enum { | |
135 EdgeMask = 3, | |
136 EdgeShift = 2, | |
137 | |
138 INITIAL_EDGE_COUNT = 4 | |
139 }; | |
140 | |
141 NodeType _type; | |
142 EscapeState _escape; | |
143 GrowableArray<uint>* _edges; // outgoing edges | |
144 int _offset; // for fields | |
145 | |
146 bool _unique_type; // For allocated objects, this node may be a unique type | |
147 public: | |
148 Node* _node; // Ideal node corresponding to this PointsTo node | |
149 int _inputs_processed; // the number of Phi inputs that have been processed so far | |
150 bool _hidden_alias; // this node is an argument to a function which may return it | |
151 // creating a hidden alias | |
152 | |
153 | |
154 PointsToNode(): _offset(-1), _type(UnknownType), _escape(UnknownEscape), _edges(NULL), _node(NULL), _inputs_processed(0), _hidden_alias(false), _unique_type(true) {} | |
155 | |
156 EscapeState escape_state() const { return _escape; } | |
157 NodeType node_type() const { return _type;} | |
158 int offset() { return _offset;} | |
159 | |
160 void set_offset(int offs) { _offset = offs;} | |
161 void set_escape_state(EscapeState state) { _escape = state; } | |
162 void set_node_type(NodeType ntype) { | |
163 assert(_type == UnknownType || _type == ntype, "Can't change node type"); | |
164 _type = ntype; | |
165 } | |
166 | |
167 // count of outgoing edges | |
168 uint edge_count() const { return (_edges == NULL) ? 0 : _edges->length(); } | |
169 // node index of target of outgoing edge "e" | |
170 uint edge_target(uint e) const; | |
171 // type of outgoing edge "e" | |
172 EdgeType edge_type(uint e) const; | |
173 // add a edge of the specified type pointing to the specified target | |
174 void add_edge(uint targIdx, EdgeType et); | |
175 // remove an edge of the specified type pointing to the specified target | |
176 void remove_edge(uint targIdx, EdgeType et); | |
177 #ifndef PRODUCT | |
178 void dump() const; | |
179 #endif | |
180 | |
181 }; | |
182 | |
183 class ConnectionGraph: public ResourceObj { | |
184 private: | |
185 enum { | |
186 INITIAL_NODE_COUNT = 100 // initial size of _nodes array | |
187 }; | |
188 | |
189 | |
190 GrowableArray<PointsToNode>* _nodes; // connection graph nodes Indexed by ideal | |
191 // node index | |
192 Unique_Node_List _deferred; // Phi's to be processed after parsing | |
193 VectorSet _processed; // records which nodes have been processed | |
194 bool _collecting; // indicates whether escape information is | |
195 // still being collected. If false, no new | |
196 // nodes will be processed | |
197 uint _phantom_object; // index of globally escaping object that | |
198 // pointer values loaded from a field which | |
199 // has not been set are assumed to point to | |
200 Compile * _compile; // Compile object for current compilation | |
201 | |
202 // address of an element in _nodes. Used when the element is to be modified | |
203 PointsToNode *ptnode_adr(uint idx) { | |
204 if ((uint)_nodes->length() <= idx) { | |
205 // expand _nodes array | |
206 PointsToNode dummy = _nodes->at_grow(idx); | |
207 } | |
208 return _nodes->adr_at(idx); | |
209 } | |
210 | |
211 // offset of a field reference | |
212 int type_to_offset(const Type *t); | |
213 | |
214 // compute the escape state for arguments to a call | |
215 void process_call_arguments(CallNode *call, PhaseTransform *phase); | |
216 | |
217 // compute the escape state for the return value of a call | |
218 void process_call_result(ProjNode *resproj, PhaseTransform *phase); | |
219 | |
220 // compute the escape state of a Phi. This may be called multiple | |
221 // times as new inputs are added to the Phi. | |
222 void process_phi_escape(PhiNode *phi, PhaseTransform *phase); | |
223 | |
224 // compute the escape state of an ideal node. | |
225 void record_escape_work(Node *n, PhaseTransform *phase); | |
226 | |
227 // walk the connection graph starting at the node corresponding to "n" and | |
228 // add the index of everything it could point to, to "ptset". This may cause | |
229 // Phi's encountered to get (re)processed (which requires "phase".) | |
230 void PointsTo(VectorSet &ptset, Node * n, PhaseTransform *phase); | |
231 | |
232 // Edge manipulation. The "from_i" and "to_i" arguments are the | |
233 // node indices of the source and destination of the edge | |
234 void add_pointsto_edge(uint from_i, uint to_i); | |
235 void add_deferred_edge(uint from_i, uint to_i); | |
236 void add_field_edge(uint from_i, uint to_i, int offs); | |
237 | |
238 | |
239 // Add an edge to node given by "to_i" from any field of adr_i whose offset | |
240 // matches "offset" A deferred edge is added if to_i is a LocalVar, and | |
241 // a pointsto edge is added if it is a JavaObject | |
242 void add_edge_from_fields(uint adr, uint to_i, int offs); | |
243 | |
244 // Add a deferred edge from node given by "from_i" to any field of adr_i whose offset | |
245 // matches "offset" | |
246 void add_deferred_edge_to_fields(uint from_i, uint adr, int offs); | |
247 | |
248 | |
249 // Remove outgoing deferred edges from the node referenced by "ni". | |
250 // Any outgoing edges from the target of the deferred edge are copied | |
251 // to "ni". | |
252 void remove_deferred(uint ni); | |
253 | |
254 Node_Array _node_map; // used for bookeeping during type splitting | |
255 // Used for the following purposes: | |
256 // Memory Phi - most recent unique Phi split out | |
257 // from this Phi | |
258 // MemNode - new memory input for this node | |
259 // ChecCastPP - allocation that this is a cast of | |
260 // allocation - CheckCastPP of the allocation | |
261 void split_AddP(Node *addp, Node *base, PhaseGVN *igvn); | |
262 PhiNode *create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn, bool &new_created); | |
263 PhiNode *split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn); | |
264 Node *find_mem(Node *mem, int alias_idx, PhaseGVN *igvn); | |
265 // Propagate unique types created for unescaped allocated objects | |
266 // through the graph | |
267 void split_unique_types(GrowableArray<Node *> &alloc_worklist); | |
268 | |
269 // manage entries in _node_map | |
270 void set_map(int idx, Node *n) { _node_map.map(idx, n); } | |
271 void set_map_phi(int idx, PhiNode *p) { _node_map.map(idx, (Node *) p); } | |
272 Node *get_map(int idx) { return _node_map[idx]; } | |
273 PhiNode *get_map_phi(int idx) { | |
274 Node *phi = _node_map[idx]; | |
275 return (phi == NULL) ? NULL : phi->as_Phi(); | |
276 } | |
277 | |
278 // Notify optimizer that a node has been modified | |
279 // Node: This assumes that escape analysis is run before | |
280 // PhaseIterGVN creation | |
281 void record_for_optimizer(Node *n) { | |
282 _compile->record_for_igvn(n); | |
283 } | |
284 | |
285 // Set the escape state of a node | |
286 void set_escape_state(uint ni, PointsToNode::EscapeState es); | |
287 | |
288 // bypass any casts and return the node they refer to | |
289 Node * skip_casts(Node *n); | |
290 | |
291 // Get Compile object for current compilation. | |
292 Compile *C() const { return _compile; } | |
293 | |
294 public: | |
295 ConnectionGraph(Compile *C); | |
296 | |
297 // record a Phi for later processing. | |
298 void record_for_escape_analysis(Node *n); | |
299 | |
300 // process a node and fill in its connection graph node | |
301 void record_escape(Node *n, PhaseTransform *phase); | |
302 | |
303 // All nodes have been recorded, compute the escape information | |
304 void compute_escape(); | |
305 | |
306 // escape state of a node | |
307 PointsToNode::EscapeState escape_state(Node *n, PhaseTransform *phase); | |
308 | |
309 bool hidden_alias(Node *n) { | |
310 if (_collecting) | |
311 return true; | |
312 PointsToNode ptn = _nodes->at_grow(n->_idx); | |
313 return (ptn.escape_state() != PointsToNode::NoEscape) || ptn._hidden_alias; | |
314 } | |
315 | |
316 #ifndef PRODUCT | |
317 void dump(); | |
318 #endif | |
319 }; |