comparison src/share/vm/prims/methodComparator.cpp @ 0:a61af66fc99e

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author duke
date Sat, 01 Dec 2007 00:00:00 +0000
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children be93aad57795
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-1:000000000000 0:108efbf48f8c
1 /*
2 * Copyright 2000-2006 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 # include "incls/_precompiled.incl"
26 # include "incls/_methodComparator.cpp.incl"
27
28 BytecodeStream *MethodComparator::_s_old;
29 BytecodeStream *MethodComparator::_s_new;
30 constantPoolOop MethodComparator::_old_cp;
31 constantPoolOop MethodComparator::_new_cp;
32 BciMap *MethodComparator::_bci_map;
33 bool MethodComparator::_switchable_test;
34 GrowableArray<int> *MethodComparator::_fwd_jmps;
35
36 bool MethodComparator::methods_EMCP(methodOop old_method, methodOop new_method) {
37 if (old_method->code_size() != new_method->code_size())
38 return false;
39 if (check_stack_and_locals_size(old_method, new_method) != 0) {
40 // RC_TRACE macro has an embedded ResourceMark
41 RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d",
42 old_method->name()->as_C_string(),
43 check_stack_and_locals_size(old_method, new_method)));
44 return false;
45 }
46
47 _old_cp = old_method->constants();
48 _new_cp = new_method->constants();
49 BytecodeStream s_old(old_method);
50 BytecodeStream s_new(new_method);
51 _s_old = &s_old;
52 _s_new = &s_new;
53 _switchable_test = false;
54 Bytecodes::Code c_old, c_new;
55
56 while ((c_old = s_old.next()) >= 0) {
57 if ((c_new = s_new.next()) < 0 || c_old != c_new)
58 return false;
59
60 if (! args_same(c_old, c_new))
61 return false;
62 }
63 return true;
64 }
65
66
67 bool MethodComparator::methods_switchable(methodOop old_method, methodOop new_method,
68 BciMap &bci_map) {
69 if (old_method->code_size() > new_method->code_size())
70 // Something has definitely been deleted in the new method, compared to the old one.
71 return false;
72
73 if (! check_stack_and_locals_size(old_method, new_method))
74 return false;
75
76 _old_cp = old_method->constants();
77 _new_cp = new_method->constants();
78 BytecodeStream s_old(old_method);
79 BytecodeStream s_new(new_method);
80 _s_old = &s_old;
81 _s_new = &s_new;
82 _bci_map = &bci_map;
83 _switchable_test = true;
84 GrowableArray<int> fwd_jmps(16);
85 _fwd_jmps = &fwd_jmps;
86 Bytecodes::Code c_old, c_new;
87
88 while ((c_old = s_old.next()) >= 0) {
89 if ((c_new = s_new.next()) < 0)
90 return false;
91 if (! (c_old == c_new && args_same(c_old, c_new))) {
92 int old_bci = s_old.bci();
93 int new_st_bci = s_new.bci();
94 bool found_match = false;
95 do {
96 c_new = s_new.next();
97 if (c_new == c_old && args_same(c_old, c_new)) {
98 found_match = true;
99 break;
100 }
101 } while (c_new >= 0);
102 if (! found_match)
103 return false;
104 int new_end_bci = s_new.bci();
105 bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci);
106 }
107 }
108
109 // Now we can test all forward jumps
110 for (int i = 0; i < fwd_jmps.length() / 2; i++) {
111 if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {
112 RC_TRACE(0x00800000,
113 ("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
114 fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),
115 fwd_jmps.at(i*2+1)));
116 return false;
117 }
118 }
119
120 return true;
121 }
122
123
124 bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
125 // BytecodeStream returns the correct standard Java bytecodes for various "fast"
126 // bytecode versions, so we don't have to bother about them here..
127 switch (c_old) {
128 case Bytecodes::_new : // fall through
129 case Bytecodes::_anewarray : // fall through
130 case Bytecodes::_multianewarray : // fall through
131 case Bytecodes::_checkcast : // fall through
132 case Bytecodes::_instanceof : {
133 u2 cpi_old = _s_old->get_index_big();
134 u2 cpi_new = _s_new->get_index_big();
135 if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new)))
136 return false;
137 if (c_old == Bytecodes::_multianewarray &&
138 *(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3))
139 return false;
140 break;
141 }
142
143 case Bytecodes::_getstatic : // fall through
144 case Bytecodes::_putstatic : // fall through
145 case Bytecodes::_getfield : // fall through
146 case Bytecodes::_putfield : // fall through
147 case Bytecodes::_invokevirtual : // fall through
148 case Bytecodes::_invokespecial : // fall through
149 case Bytecodes::_invokestatic : // fall through
150 case Bytecodes::_invokeinterface : {
151 u2 cpci_old = _s_old->get_index_big();
152 u2 cpci_new = _s_new->get_index_big();
153 // Check if the names of classes, field/method names and signatures at these indexes
154 // are the same. Indices which are really into constantpool cache (rather than constant
155 // pool itself) are accepted by the constantpool query routines below.
156 if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) ||
157 (_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
158 (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
159 return false;
160 break;
161 }
162
163 case Bytecodes::_ldc : // fall through
164 case Bytecodes::_ldc_w : {
165 u2 cpi_old, cpi_new;
166 if (c_old == Bytecodes::_ldc) {
167 cpi_old = _s_old->bcp()[1];
168 cpi_new = _s_new->bcp()[1];
169 } else {
170 cpi_old = _s_old->get_index_big();
171 cpi_new = _s_new->get_index_big();
172 }
173 constantTag tag_old = _old_cp->tag_at(cpi_old);
174 constantTag tag_new = _new_cp->tag_at(cpi_new);
175 if (tag_old.is_int() || tag_old.is_float()) {
176 if (tag_old.value() != tag_new.value())
177 return false;
178 if (tag_old.is_int()) {
179 if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new))
180 return false;
181 } else {
182 if (_old_cp->float_at(cpi_old) != _new_cp->float_at(cpi_new))
183 return false;
184 }
185 } else if (tag_old.is_string() || tag_old.is_unresolved_string()) {
186 if (! (tag_new.is_unresolved_string() || tag_new.is_string()))
187 return false;
188 if (strcmp(_old_cp->string_at_noresolve(cpi_old),
189 _new_cp->string_at_noresolve(cpi_new)) != 0)
190 return false;
191 } else { // tag_old should be klass - 4881222
192 if (! (tag_new.is_unresolved_klass() || tag_new.is_klass()))
193 return false;
194 if (_old_cp->klass_at_noresolve(cpi_old) !=
195 _new_cp->klass_at_noresolve(cpi_new))
196 return false;
197 }
198 break;
199 }
200
201 case Bytecodes::_ldc2_w : {
202 u2 cpi_old = _s_old->get_index_big();
203 u2 cpi_new = _s_new->get_index_big();
204 constantTag tag_old = _old_cp->tag_at(cpi_old);
205 constantTag tag_new = _new_cp->tag_at(cpi_new);
206 if (tag_old.value() != tag_new.value())
207 return false;
208 if (tag_old.is_long()) {
209 if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new))
210 return false;
211 } else {
212 if (_old_cp->double_at(cpi_old) != _new_cp->double_at(cpi_new))
213 return false;
214 }
215 break;
216 }
217
218 case Bytecodes::_bipush :
219 if (_s_old->bcp()[1] != _s_new->bcp()[1])
220 return false;
221 break;
222
223 case Bytecodes::_sipush :
224 if (_s_old->get_index_big() != _s_new->get_index_big())
225 return false;
226 break;
227
228 case Bytecodes::_aload : // fall through
229 case Bytecodes::_astore : // fall through
230 case Bytecodes::_dload : // fall through
231 case Bytecodes::_dstore : // fall through
232 case Bytecodes::_fload : // fall through
233 case Bytecodes::_fstore : // fall through
234 case Bytecodes::_iload : // fall through
235 case Bytecodes::_istore : // fall through
236 case Bytecodes::_lload : // fall through
237 case Bytecodes::_lstore : // fall through
238 case Bytecodes::_ret :
239 if (_s_old->is_wide() != _s_new->is_wide())
240 return false;
241 if (_s_old->get_index() != _s_new->get_index())
242 return false;
243 break;
244
245 case Bytecodes::_goto : // fall through
246 case Bytecodes::_if_acmpeq : // fall through
247 case Bytecodes::_if_acmpne : // fall through
248 case Bytecodes::_if_icmpeq : // fall through
249 case Bytecodes::_if_icmpne : // fall through
250 case Bytecodes::_if_icmplt : // fall through
251 case Bytecodes::_if_icmpge : // fall through
252 case Bytecodes::_if_icmpgt : // fall through
253 case Bytecodes::_if_icmple : // fall through
254 case Bytecodes::_ifeq : // fall through
255 case Bytecodes::_ifne : // fall through
256 case Bytecodes::_iflt : // fall through
257 case Bytecodes::_ifge : // fall through
258 case Bytecodes::_ifgt : // fall through
259 case Bytecodes::_ifle : // fall through
260 case Bytecodes::_ifnonnull : // fall through
261 case Bytecodes::_ifnull : // fall through
262 case Bytecodes::_jsr : {
263 short old_ofs = (short) _s_old->get_index_big();
264 short new_ofs = (short) _s_new->get_index_big();
265 if (_switchable_test) {
266 int old_dest = _s_old->bci() + old_ofs;
267 int new_dest = _s_new->bci() + new_ofs;
268 if (old_ofs < 0 && new_ofs < 0) {
269 if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
270 return false;
271 } else if (old_ofs > 0 && new_ofs > 0) {
272 _fwd_jmps->append(old_dest);
273 _fwd_jmps->append(new_dest);
274 } else {
275 return false;
276 }
277 } else {
278 if (old_ofs != new_ofs)
279 return false;
280 }
281 break;
282 }
283
284 case Bytecodes::_iinc :
285 if (_s_old->is_wide() != _s_new->is_wide())
286 return false;
287 if (! _s_old->is_wide()) {
288 if (_s_old->get_index_big() != _s_new->get_index_big())
289 return false;
290 } else {
291 if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1))
292 return false;
293 }
294 break;
295
296 case Bytecodes::_goto_w : // fall through
297 case Bytecodes::_jsr_w : {
298 int old_ofs = (int) Bytes::get_Java_u4(_s_old->bcp() + 1);
299 int new_ofs = (int) Bytes::get_Java_u4(_s_new->bcp() + 1);
300 if (_switchable_test) {
301 int old_dest = _s_old->bci() + old_ofs;
302 int new_dest = _s_new->bci() + new_ofs;
303 if (old_ofs < 0 && new_ofs < 0) {
304 if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
305 return false;
306 } else if (old_ofs > 0 && new_ofs > 0) {
307 _fwd_jmps->append(old_dest);
308 _fwd_jmps->append(new_dest);
309 } else {
310 return false;
311 }
312 } else {
313 if (old_ofs != new_ofs)
314 return false;
315 }
316 break;
317 }
318
319 case Bytecodes::_lookupswitch : // fall through
320 case Bytecodes::_tableswitch : {
321 if (_switchable_test) {
322 address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);
323 address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);
324 int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);
325 int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);
326 _fwd_jmps->append(_s_old->bci() + default_old);
327 _fwd_jmps->append(_s_new->bci() + default_new);
328 if (c_old == Bytecodes::_lookupswitch) {
329 int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
330 int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
331 if (npairs_old != npairs_new)
332 return false;
333 for (int i = 0; i < npairs_old; i++) {
334 int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);
335 int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);
336 if (match_old != match_new)
337 return false;
338 int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);
339 int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);
340 _fwd_jmps->append(_s_old->bci() + ofs_old);
341 _fwd_jmps->append(_s_new->bci() + ofs_new);
342 }
343 } else if (c_old == Bytecodes::_tableswitch) {
344 int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
345 int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
346 if (lo_old != lo_new)
347 return false;
348 int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);
349 int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);
350 if (hi_old != hi_new)
351 return false;
352 for (int i = 0; i < hi_old - lo_old + 1; i++) {
353 int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);
354 int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);
355 _fwd_jmps->append(_s_old->bci() + ofs_old);
356 _fwd_jmps->append(_s_new->bci() + ofs_new);
357 }
358 }
359 } else { // !_switchable_test, can use fast rough compare
360 int len_old = _s_old->next_bcp() - _s_old->bcp();
361 int len_new = _s_new->next_bcp() - _s_new->bcp();
362 if (len_old != len_new)
363 return false;
364 if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
365 return false;
366 }
367 break;
368 }
369 }
370
371 return true;
372 }
373
374
375 int MethodComparator::check_stack_and_locals_size(methodOop old_method, methodOop new_method) {
376 if (old_method->max_stack() != new_method->max_stack()) {
377 return 1;
378 } else if (old_method->max_locals() != new_method->max_locals()) {
379 return 2;
380 } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) {
381 return 3;
382 } else return 0;
383 }