Mercurial > hg > graal-compiler
annotate src/share/vm/runtime/relocator.cpp @ 1552:c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair
| author | trims |
|---|---|
| date | Thu, 27 May 2010 19:08:38 -0700 |
| parents | a61af66fc99e |
| children | a4c7fe54bf3f |
| rev | line source |
|---|---|
| 0 | 1 /* |
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2 * Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
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20 * or visit www.oracle.com if you need additional information or have any |
|
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 # include "incls/_precompiled.incl" | |
| 26 # include "incls/_relocator.cpp.incl" | |
| 27 | |
| 28 #define MAX_METHOD_LENGTH 65535 | |
| 29 | |
| 30 #define MAX_SHORT ((1 << 15) - 1) | |
| 31 #define MIN_SHORT (- (1 << 15)) | |
| 32 | |
| 33 // Encapsulates a code change request. There are 3 types. | |
| 34 // General instruction, jump instruction, and table/lookup switches | |
| 35 // | |
| 36 class ChangeItem : public ResourceObj { | |
| 37 int _bci; | |
| 38 public: | |
| 39 ChangeItem(int bci) { _bci = bci; } | |
| 40 virtual bool handle_code_change(Relocator *r) = 0; | |
| 41 | |
| 42 // type info | |
| 43 virtual bool is_widen() { return false; } | |
| 44 virtual bool is_jump_widen() { return false; } | |
| 45 virtual bool is_switch_pad() { return false; } | |
| 46 | |
| 47 // accessors | |
| 48 int bci() { return _bci; } | |
| 49 void relocate(int break_bci, int delta) { if (_bci > break_bci) { _bci += delta; } } | |
| 50 | |
| 51 virtual bool adjust(int bci, int delta) { return false; } | |
| 52 | |
| 53 // debug | |
| 54 virtual void print() = 0; | |
| 55 }; | |
| 56 | |
| 57 class ChangeWiden : public ChangeItem { | |
| 58 int _new_ilen; // New length of instruction at bci | |
| 59 u_char* _inst_buffer; // New bytecodes | |
| 60 public: | |
| 61 ChangeWiden(int bci, int new_ilen, u_char* inst_buffer) : ChangeItem(bci) { | |
| 62 _new_ilen = new_ilen; | |
| 63 _inst_buffer = inst_buffer; | |
| 64 } | |
| 65 | |
| 66 // Callback to do instruction | |
| 67 bool handle_code_change(Relocator *r) { return r->handle_widen(bci(), _new_ilen, _inst_buffer); }; | |
| 68 | |
| 69 bool is_widen() { return true; } | |
| 70 | |
| 71 void print() { tty->print_cr("ChangeWiden. bci: %d New_ilen: %d", bci(), _new_ilen); } | |
| 72 }; | |
| 73 | |
| 74 class ChangeJumpWiden : public ChangeItem { | |
| 75 int _delta; // New length of instruction at bci | |
| 76 public: | |
| 77 ChangeJumpWiden(int bci, int delta) : ChangeItem(bci) { _delta = delta; } | |
| 78 | |
| 79 // Callback to do instruction | |
| 80 bool handle_code_change(Relocator *r) { return r->handle_jump_widen(bci(), _delta); }; | |
| 81 | |
| 82 bool is_jump_widen() { return true; } | |
| 83 | |
| 84 // If the bci matches, adjust the delta in the change jump request. | |
| 85 bool adjust(int jump_bci, int delta) { | |
| 86 if (bci() == jump_bci) { | |
| 87 if (_delta > 0) | |
| 88 _delta += delta; | |
| 89 else | |
| 90 _delta -= delta; | |
| 91 return true; | |
| 92 } | |
| 93 return false; | |
| 94 } | |
| 95 | |
| 96 void print() { tty->print_cr("ChangeJumpWiden. bci: %d Delta: %d", bci(), _delta); } | |
| 97 }; | |
| 98 | |
| 99 class ChangeSwitchPad : public ChangeItem { | |
| 100 int _padding; | |
| 101 bool _is_lookup_switch; | |
| 102 public: | |
| 103 ChangeSwitchPad(int bci, int padding, bool is_lookup_switch) : ChangeItem(bci) { | |
| 104 _padding = padding; | |
| 105 _is_lookup_switch = is_lookup_switch; | |
| 106 } | |
| 107 | |
| 108 // Callback to do instruction | |
| 109 bool handle_code_change(Relocator *r) { return r->handle_switch_pad(bci(), _padding, _is_lookup_switch); }; | |
| 110 | |
| 111 bool is_switch_pad() { return true; } | |
| 112 int padding() { return _padding; } | |
| 113 bool is_lookup_switch() { return _is_lookup_switch; } | |
| 114 | |
| 115 void print() { tty->print_cr("ChangeSwitchPad. bci: %d Padding: %d IsLookupSwitch: %d", bci(), _padding, _is_lookup_switch); } | |
| 116 }; | |
| 117 | |
| 118 //----------------------------------------------------------------------------------------------------------- | |
| 119 // Relocator code | |
| 120 | |
| 121 Relocator::Relocator(methodHandle m, RelocatorListener* listener) { | |
| 122 set_method(m); | |
| 123 set_code_length(method()->code_size()); | |
| 124 set_code_array(NULL); | |
| 125 // Allocate code array and copy bytecodes | |
| 126 if (!expand_code_array(0)) { | |
| 127 // Should have at least MAX_METHOD_LENGTH available or the verifier | |
| 128 // would have failed. | |
| 129 ShouldNotReachHere(); | |
| 130 } | |
| 131 set_compressed_line_number_table(NULL); | |
| 132 set_compressed_line_number_table_size(0); | |
| 133 _listener = listener; | |
| 134 } | |
| 135 | |
| 136 // size is the new size of the instruction at bci. Hence, if size is less than the current | |
| 137 // instruction sice, we will shrink the code. | |
| 138 methodHandle Relocator::insert_space_at(int bci, int size, u_char inst_buffer[], TRAPS) { | |
| 139 _changes = new GrowableArray<ChangeItem*> (10); | |
| 140 _changes->push(new ChangeWiden(bci, size, inst_buffer)); | |
| 141 | |
| 142 if (TraceRelocator) { | |
| 143 tty->print_cr("Space at: %d Size: %d", bci, size); | |
| 144 _method->print(); | |
| 145 _method->print_codes(); | |
| 146 tty->print_cr("-------------------------------------------------"); | |
| 147 } | |
| 148 | |
| 149 if (!handle_code_changes()) return methodHandle(); | |
| 150 | |
| 151 // Construct the new method | |
| 152 methodHandle new_method = methodOopDesc::clone_with_new_data(method(), | |
| 153 code_array(), code_length(), | |
| 154 compressed_line_number_table(), | |
| 155 compressed_line_number_table_size(), | |
| 156 CHECK_(methodHandle())); | |
| 157 set_method(new_method); | |
| 158 | |
| 159 if (TraceRelocator) { | |
| 160 tty->print_cr("-------------------------------------------------"); | |
| 161 tty->print_cr("new method"); | |
| 162 _method->print_codes(); | |
| 163 } | |
| 164 | |
| 165 return new_method; | |
| 166 } | |
| 167 | |
| 168 | |
| 169 bool Relocator::handle_code_changes() { | |
| 170 assert(_changes != NULL, "changes vector must be initialized"); | |
| 171 | |
| 172 while (!_changes->is_empty()) { | |
| 173 // Inv: everything is aligned. | |
| 174 ChangeItem* ci = _changes->first(); | |
| 175 | |
| 176 if (TraceRelocator) { | |
| 177 ci->print(); | |
| 178 } | |
| 179 | |
| 180 // Execute operation | |
| 181 if (!ci->handle_code_change(this)) return false; | |
| 182 | |
| 183 // Shuffel items up | |
| 184 for (int index = 1; index < _changes->length(); index++) { | |
| 185 _changes->at_put(index-1, _changes->at(index)); | |
| 186 } | |
| 187 _changes->pop(); | |
| 188 } | |
| 189 return true; | |
| 190 } | |
| 191 | |
| 192 | |
| 193 bool Relocator::is_opcode_lookupswitch(Bytecodes::Code bc) { | |
| 194 switch (bc) { | |
| 195 case Bytecodes::_tableswitch: return false; | |
| 196 case Bytecodes::_lookupswitch: // not rewritten on ia64 | |
| 197 case Bytecodes::_fast_linearswitch: // rewritten _lookupswitch | |
| 198 case Bytecodes::_fast_binaryswitch: return true; // rewritten _lookupswitch | |
| 199 default: ShouldNotReachHere(); | |
| 200 } | |
| 201 return true; // dummy | |
| 202 } | |
| 203 | |
| 204 // We need a special instruction size method, since lookupswitches and tableswitches might not be | |
| 205 // properly alligned during relocation | |
| 206 int Relocator::rc_instr_len(int bci) { | |
| 207 Bytecodes::Code bc= code_at(bci); | |
| 208 switch (bc) { | |
| 209 // In the case of switch instructions, see if we have the original | |
| 210 // padding recorded. | |
| 211 case Bytecodes::_tableswitch: | |
| 212 case Bytecodes::_lookupswitch: | |
| 213 case Bytecodes::_fast_linearswitch: | |
| 214 case Bytecodes::_fast_binaryswitch: | |
| 215 { | |
| 216 int pad = get_orig_switch_pad(bci, is_opcode_lookupswitch(bc)); | |
| 217 if (pad == -1) { | |
| 218 return instruction_length_at(bci); | |
| 219 } | |
| 220 // Otherwise, depends on the switch type. | |
| 221 switch (bc) { | |
| 222 case Bytecodes::_tableswitch: { | |
| 223 int lo = int_at(bci + 1 + pad + 4 * 1); | |
| 224 int hi = int_at(bci + 1 + pad + 4 * 2); | |
| 225 int n = hi - lo + 1; | |
| 226 return 1 + pad + 4*(3 + n); | |
| 227 } | |
| 228 case Bytecodes::_lookupswitch: | |
| 229 case Bytecodes::_fast_linearswitch: | |
| 230 case Bytecodes::_fast_binaryswitch: { | |
| 231 int npairs = int_at(bci + 1 + pad + 4 * 1); | |
| 232 return 1 + pad + 4*(2 + 2*npairs); | |
| 233 } | |
| 234 default: | |
| 235 ShouldNotReachHere(); | |
| 236 } | |
| 237 } | |
| 238 } | |
| 239 return instruction_length_at(bci); | |
| 240 } | |
| 241 | |
| 242 // If a change item is recorded for "pc", with type "ct", returns the | |
| 243 // associated padding, else -1. | |
| 244 int Relocator::get_orig_switch_pad(int bci, bool is_lookup_switch) { | |
| 245 for (int k = 0; k < _changes->length(); k++) { | |
| 246 ChangeItem* ci = _changes->at(k); | |
| 247 if (ci->is_switch_pad()) { | |
| 248 ChangeSwitchPad* csp = (ChangeSwitchPad*)ci; | |
| 249 if (csp->is_lookup_switch() == is_lookup_switch && csp->bci() == bci) { | |
| 250 return csp->padding(); | |
| 251 } | |
| 252 } | |
| 253 } | |
| 254 return -1; | |
| 255 } | |
| 256 | |
| 257 | |
| 258 // Push a ChangeJumpWiden if it doesn't already exist on the work queue, | |
| 259 // otherwise adjust the item already there by delta. The calculation for | |
| 260 // new_delta is wrong for this because it uses the offset stored in the | |
| 261 // code stream itself which wasn't fixed when item was pushed on the work queue. | |
| 262 void Relocator::push_jump_widen(int bci, int delta, int new_delta) { | |
| 263 for (int j = 0; j < _changes->length(); j++) { | |
| 264 ChangeItem* ci = _changes->at(j); | |
| 265 if (ci->adjust(bci, delta)) return; | |
| 266 } | |
| 267 _changes->push(new ChangeJumpWiden(bci, new_delta)); | |
| 268 } | |
| 269 | |
| 270 | |
| 271 // The current instruction of "c" is a jump; one of its offset starts | |
| 272 // at "offset" and is a short if "isShort" is "TRUE", | |
| 273 // and an integer otherwise. If the jump crosses "breakPC", change | |
| 274 // the span of the jump by "delta". | |
| 275 void Relocator::change_jump(int bci, int offset, bool is_short, int break_bci, int delta) { | |
| 276 int bci_delta = (is_short) ? short_at(offset) : int_at(offset); | |
| 277 int targ = bci + bci_delta; | |
| 278 | |
| 279 if ((bci <= break_bci && targ > break_bci) || | |
| 280 (bci > break_bci && targ <= break_bci)) { | |
| 281 int new_delta; | |
| 282 if (bci_delta > 0) | |
| 283 new_delta = bci_delta + delta; | |
| 284 else | |
| 285 new_delta = bci_delta - delta; | |
| 286 | |
| 287 if (is_short && ((new_delta > MAX_SHORT) || new_delta < MIN_SHORT)) { | |
| 288 push_jump_widen(bci, delta, new_delta); | |
| 289 } else if (is_short) { | |
| 290 short_at_put(offset, new_delta); | |
| 291 } else { | |
| 292 int_at_put(offset, new_delta); | |
| 293 } | |
| 294 } | |
| 295 } | |
| 296 | |
| 297 | |
| 298 // Changes all jumps crossing "break_bci" by "delta". May enqueue things | |
| 299 // on "rc->changes" | |
| 300 void Relocator::change_jumps(int break_bci, int delta) { | |
| 301 int bci = 0; | |
| 302 Bytecodes::Code bc; | |
| 303 // Now, adjust any affected instructions. | |
| 304 while (bci < code_length()) { | |
| 305 switch (bc= code_at(bci)) { | |
| 306 case Bytecodes::_ifeq: | |
| 307 case Bytecodes::_ifne: | |
| 308 case Bytecodes::_iflt: | |
| 309 case Bytecodes::_ifge: | |
| 310 case Bytecodes::_ifgt: | |
| 311 case Bytecodes::_ifle: | |
| 312 case Bytecodes::_if_icmpeq: | |
| 313 case Bytecodes::_if_icmpne: | |
| 314 case Bytecodes::_if_icmplt: | |
| 315 case Bytecodes::_if_icmpge: | |
| 316 case Bytecodes::_if_icmpgt: | |
| 317 case Bytecodes::_if_icmple: | |
| 318 case Bytecodes::_if_acmpeq: | |
| 319 case Bytecodes::_if_acmpne: | |
| 320 case Bytecodes::_ifnull: | |
| 321 case Bytecodes::_ifnonnull: | |
| 322 case Bytecodes::_goto: | |
| 323 case Bytecodes::_jsr: | |
| 324 change_jump(bci, bci+1, true, break_bci, delta); | |
| 325 break; | |
| 326 case Bytecodes::_goto_w: | |
| 327 case Bytecodes::_jsr_w: | |
| 328 change_jump(bci, bci+1, false, break_bci, delta); | |
| 329 break; | |
| 330 case Bytecodes::_tableswitch: | |
| 331 case Bytecodes::_lookupswitch: | |
| 332 case Bytecodes::_fast_linearswitch: | |
| 333 case Bytecodes::_fast_binaryswitch: { | |
| 334 int recPad = get_orig_switch_pad(bci, (bc != Bytecodes::_tableswitch)); | |
| 335 int oldPad = (recPad != -1) ? recPad : align(bci+1) - (bci+1); | |
| 336 if (bci > break_bci) { | |
| 337 int new_bci = bci + delta; | |
| 338 int newPad = align(new_bci+1) - (new_bci+1); | |
| 339 // Do we need to check the padding? | |
| 340 if (newPad != oldPad) { | |
| 341 if (recPad == -1) { | |
| 342 _changes->push(new ChangeSwitchPad(bci, oldPad, (bc != Bytecodes::_tableswitch))); | |
| 343 } | |
| 344 } | |
| 345 } | |
| 346 | |
| 347 // Then the rest, which depend on the kind of switch. | |
| 348 switch (bc) { | |
| 349 case Bytecodes::_tableswitch: { | |
| 350 change_jump(bci, bci +1 + oldPad, false, break_bci, delta); | |
| 351 // We cannot use the Bytecode_tableswitch abstraction, since the padding might not be correct. | |
| 352 int lo = int_at(bci + 1 + oldPad + 4 * 1); | |
| 353 int hi = int_at(bci + 1 + oldPad + 4 * 2); | |
| 354 int n = hi - lo + 1; | |
| 355 for (int k = 0; k < n; k++) { | |
| 356 change_jump(bci, bci +1 + oldPad + 4*(k+3), false, break_bci, delta); | |
| 357 } | |
| 358 // Special next-bci calculation here... | |
| 359 bci += 1 + oldPad + (n+3)*4; | |
| 360 continue; | |
| 361 } | |
| 362 case Bytecodes::_lookupswitch: | |
| 363 case Bytecodes::_fast_linearswitch: | |
| 364 case Bytecodes::_fast_binaryswitch: { | |
| 365 change_jump(bci, bci +1 + oldPad, false, break_bci, delta); | |
| 366 // We cannot use the Bytecode_lookupswitch abstraction, since the padding might not be correct. | |
| 367 int npairs = int_at(bci + 1 + oldPad + 4 * 1); | |
| 368 for (int k = 0; k < npairs; k++) { | |
| 369 change_jump(bci, bci + 1 + oldPad + 4*(2 + 2*k + 1), false, break_bci, delta); | |
| 370 } | |
| 371 /* Special next-bci calculation here... */ | |
| 372 bci += 1 + oldPad + (2 + (npairs*2))*4; | |
| 373 continue; | |
| 374 } | |
| 375 default: | |
| 376 ShouldNotReachHere(); | |
| 377 } | |
| 378 } | |
| 379 default: | |
| 380 break; | |
| 381 } | |
| 382 bci += rc_instr_len(bci); | |
| 383 } | |
| 384 } | |
| 385 | |
| 386 // The width of instruction at "pc" is changing by "delta". Adjust the | |
| 387 // exception table, if any, of "rc->mb". | |
| 388 void Relocator::adjust_exception_table(int bci, int delta) { | |
| 389 typeArrayOop table = method()->exception_table(); | |
| 390 for (int index = 0; index < table->length(); index +=4) { | |
| 391 if (table->int_at(index) > bci) { | |
| 392 table->int_at_put(index+0, table->int_at(index+0) + delta); | |
| 393 table->int_at_put(index+1, table->int_at(index+1) + delta); | |
| 394 } else if (bci < table->int_at(index+1)) { | |
| 395 table->int_at_put(index+1, table->int_at(index+1) + delta); | |
| 396 } | |
| 397 if (table->int_at(index+2) > bci) | |
| 398 table->int_at_put(index+2, table->int_at(index+2) + delta); | |
| 399 } | |
| 400 } | |
| 401 | |
| 402 | |
| 403 // The width of instruction at "bci" is changing by "delta". Adjust the line number table. | |
| 404 void Relocator::adjust_line_no_table(int bci, int delta) { | |
| 405 if (method()->has_linenumber_table()) { | |
| 406 CompressedLineNumberReadStream reader(method()->compressed_linenumber_table()); | |
| 407 CompressedLineNumberWriteStream writer(64); // plenty big for most line number tables | |
| 408 while (reader.read_pair()) { | |
| 409 int adjustment = (reader.bci() > bci) ? delta : 0; | |
| 410 writer.write_pair(reader.bci() + adjustment, reader.line()); | |
| 411 } | |
| 412 writer.write_terminator(); | |
| 413 set_compressed_line_number_table(writer.buffer()); | |
| 414 set_compressed_line_number_table_size(writer.position()); | |
| 415 } | |
| 416 } | |
| 417 | |
| 418 | |
| 419 // The width of instruction at "bci" is changing by "delta". Adjust the local variable table. | |
| 420 void Relocator::adjust_local_var_table(int bci, int delta) { | |
| 421 int localvariable_table_length = method()->localvariable_table_length(); | |
| 422 if (localvariable_table_length > 0) { | |
| 423 LocalVariableTableElement* table = method()->localvariable_table_start(); | |
| 424 for (int i = 0; i < localvariable_table_length; i++) { | |
| 425 u2 current_bci = table[i].start_bci; | |
| 426 if (current_bci > bci) { | |
| 427 table[i].start_bci = current_bci + delta; | |
| 428 } else { | |
| 429 u2 current_length = table[i].length; | |
| 430 if (current_bci + current_length > bci) { | |
| 431 table[i].length = current_length + delta; | |
| 432 } | |
| 433 } | |
| 434 } | |
| 435 } | |
| 436 } | |
| 437 | |
| 438 | |
| 439 bool Relocator::expand_code_array(int delta) { | |
| 440 int length = MAX2(code_length() + delta, code_length() * (100+code_slop_pct()) / 100); | |
| 441 | |
| 442 if (length > MAX_METHOD_LENGTH) { | |
| 443 if (delta == 0 && code_length() <= MAX_METHOD_LENGTH) { | |
| 444 length = MAX_METHOD_LENGTH; | |
| 445 } else { | |
| 446 return false; | |
| 447 } | |
| 448 } | |
| 449 | |
| 450 unsigned char* new_code_array = NEW_RESOURCE_ARRAY(unsigned char, length); | |
| 451 if (!new_code_array) return false; | |
| 452 | |
| 453 // Expanding current array | |
| 454 if (code_array() != NULL) { | |
| 455 memcpy(new_code_array, code_array(), code_length()); | |
| 456 } else { | |
| 457 // Initial copy. Copy directly from methodOop | |
| 458 memcpy(new_code_array, method()->code_base(), code_length()); | |
| 459 } | |
| 460 | |
| 461 set_code_array(new_code_array); | |
| 462 set_code_array_length(length); | |
| 463 | |
| 464 return true; | |
| 465 } | |
| 466 | |
| 467 | |
| 468 // The instruction at "bci", whose size is "ilen", is changing size by | |
| 469 // "delta". Reallocate, move code, recalculate jumps, and enqueue | |
| 470 // change items as necessary. | |
| 471 bool Relocator::relocate_code(int bci, int ilen, int delta) { | |
| 472 int next_bci = bci + ilen; | |
| 473 if (delta > 0 && code_length() + delta > code_array_length()) { | |
| 474 // Expand allocated code space, if necessary. | |
| 475 if (!expand_code_array(delta)) { | |
| 476 return false; | |
| 477 } | |
| 478 } | |
| 479 | |
| 480 // We require 4-byte alignment of code arrays. | |
| 481 assert(((intptr_t)code_array() & 3) == 0, "check code alignment"); | |
| 482 // Change jumps before doing the copying; this routine requires aligned switches. | |
| 483 change_jumps(bci, delta); | |
| 484 | |
| 485 // In case we have shrunken a tableswitch/lookupswitch statement, we store the last | |
| 486 // bytes that get overwritten. We have to copy the bytes after the change_jumps method | |
| 487 // has been called, since it is likly to update last offset in a tableswitch/lookupswitch | |
| 488 if (delta < 0) { | |
| 489 assert(delta>=-3, "we cannot overwrite more than 3 bytes"); | |
| 490 memcpy(_overwrite, addr_at(bci + ilen + delta), -delta); | |
| 491 } | |
| 492 | |
| 493 memmove(addr_at(next_bci + delta), addr_at(next_bci), code_length() - next_bci); | |
| 494 set_code_length(code_length() + delta); | |
| 495 // Also adjust exception tables... | |
| 496 adjust_exception_table(bci, delta); | |
| 497 // Line number tables... | |
| 498 adjust_line_no_table(bci, delta); | |
| 499 // And local variable table... | |
| 500 adjust_local_var_table(bci, delta); | |
| 501 | |
| 502 // Relocate the pending change stack... | |
| 503 for (int j = 0; j < _changes->length(); j++) { | |
| 504 ChangeItem* ci = _changes->at(j); | |
| 505 ci->relocate(bci, delta); | |
| 506 } | |
| 507 | |
| 508 // Notify any listeners about code relocation | |
| 509 notify(bci, delta, code_length()); | |
| 510 | |
| 511 return true; | |
| 512 } | |
| 513 | |
| 514 // relocate a general instruction. Called by ChangeWiden class | |
| 515 bool Relocator::handle_widen(int bci, int new_ilen, u_char inst_buffer[]) { | |
| 516 int ilen = rc_instr_len(bci); | |
| 517 if (!relocate_code(bci, ilen, new_ilen - ilen)) | |
| 518 return false; | |
| 519 | |
| 520 // Insert new bytecode(s) | |
| 521 for(int k = 0; k < new_ilen; k++) { | |
| 522 code_at_put(bci + k, (Bytecodes::Code)inst_buffer[k]); | |
| 523 } | |
| 524 | |
| 525 return true; | |
| 526 } | |
| 527 | |
| 528 // handle jump_widen instruction. Called be ChangeJumpWiden class | |
| 529 bool Relocator::handle_jump_widen(int bci, int delta) { | |
| 530 int ilen = rc_instr_len(bci); | |
| 531 | |
| 532 Bytecodes::Code bc = code_at(bci); | |
| 533 switch (bc) { | |
| 534 case Bytecodes::_ifeq: | |
| 535 case Bytecodes::_ifne: | |
| 536 case Bytecodes::_iflt: | |
| 537 case Bytecodes::_ifge: | |
| 538 case Bytecodes::_ifgt: | |
| 539 case Bytecodes::_ifle: | |
| 540 case Bytecodes::_if_icmpeq: | |
| 541 case Bytecodes::_if_icmpne: | |
| 542 case Bytecodes::_if_icmplt: | |
| 543 case Bytecodes::_if_icmpge: | |
| 544 case Bytecodes::_if_icmpgt: | |
| 545 case Bytecodes::_if_icmple: | |
| 546 case Bytecodes::_if_acmpeq: | |
| 547 case Bytecodes::_if_acmpne: | |
| 548 case Bytecodes::_ifnull: | |
| 549 case Bytecodes::_ifnonnull: { | |
| 550 const int goto_length = Bytecodes::length_for(Bytecodes::_goto); | |
| 551 | |
| 552 // If 'if' points to the next bytecode after goto, it's already handled. | |
| 553 // it shouldn't be. | |
| 554 assert (short_at(bci+1) != ilen+goto_length, "if relocation already handled"); | |
| 555 assert(ilen == 3, "check length"); | |
| 556 | |
| 557 // Convert to 0 if <cond> goto 6 | |
| 558 // 3 _goto 11 | |
| 559 // 6 _goto_w <wide delta offset> | |
| 560 // 11 <else code> | |
| 561 const int goto_w_length = Bytecodes::length_for(Bytecodes::_goto_w); | |
| 562 const int add_bci = goto_length + goto_w_length; | |
| 563 | |
| 564 if (!relocate_code(bci, 3, /*delta*/add_bci)) return false; | |
| 565 | |
| 566 // if bytecode points to goto_w instruction | |
| 567 short_at_put(bci + 1, ilen + goto_length); | |
| 568 | |
| 569 int cbci = bci + ilen; | |
| 570 // goto around | |
| 571 code_at_put(cbci, Bytecodes::_goto); | |
| 572 short_at_put(cbci + 1, add_bci); | |
| 573 // goto_w <wide delta> | |
| 574 cbci = cbci + goto_length; | |
| 575 code_at_put(cbci, Bytecodes::_goto_w); | |
| 576 if (delta > 0) { | |
| 577 delta += 2; // goto_w is 2 bytes more than "if" code | |
| 578 } else { | |
| 579 delta -= ilen+goto_length; // branch starts at goto_w offset | |
| 580 } | |
| 581 int_at_put(cbci + 1, delta); | |
| 582 break; | |
| 583 | |
| 584 } | |
| 585 case Bytecodes::_goto: | |
| 586 case Bytecodes::_jsr: | |
| 587 assert(ilen == 3, "check length"); | |
| 588 | |
| 589 if (!relocate_code(bci, 3, 2)) return false; | |
| 590 if (bc == Bytecodes::_goto) | |
| 591 code_at_put(bci, Bytecodes::_goto_w); | |
| 592 else | |
| 593 code_at_put(bci, Bytecodes::_jsr_w); | |
| 594 | |
| 595 // If it's a forward jump, add 2 for the widening. | |
| 596 if (delta > 0) delta += 2; | |
| 597 int_at_put(bci + 1, delta); | |
| 598 break; | |
| 599 | |
| 600 default: ShouldNotReachHere(); | |
| 601 } | |
| 602 | |
| 603 return true; | |
| 604 } | |
| 605 | |
| 606 // handle lookup/table switch instructions. Called be ChangeSwitchPad class | |
| 607 bool Relocator::handle_switch_pad(int bci, int old_pad, bool is_lookup_switch) { | |
| 608 int ilen = rc_instr_len(bci); | |
| 609 int new_pad = align(bci+1) - (bci+1); | |
| 610 int pad_delta = new_pad - old_pad; | |
| 611 if (pad_delta != 0) { | |
| 612 int len; | |
| 613 if (!is_lookup_switch) { | |
| 614 int low = int_at(bci+1+old_pad+4); | |
| 615 int high = int_at(bci+1+old_pad+8); | |
| 616 len = high-low+1 + 3; // 3 for default, hi, lo. | |
| 617 } else { | |
| 618 int npairs = int_at(bci+1+old_pad+4); | |
| 619 len = npairs*2 + 2; // 2 for default, npairs. | |
| 620 } | |
| 621 // Because "relocateCode" does a "changeJumps" loop, | |
| 622 // which parses instructions to determine their length, | |
| 623 // we need to call that before messing with the current | |
| 624 // instruction. Since it may also overwrite the current | |
| 625 // instruction when moving down, remember the possibly | |
| 626 // overwritten part. | |
| 627 | |
| 628 // Move the code following the instruction... | |
| 629 if (!relocate_code(bci, ilen, pad_delta)) return false; | |
| 630 | |
| 631 if (pad_delta < 0) { | |
| 632 // Move the shrunken instruction down. | |
| 633 memmove(addr_at(bci + 1 + new_pad), | |
| 634 addr_at(bci + 1 + old_pad), | |
| 635 len * 4 + pad_delta); | |
| 636 memmove(addr_at(bci + 1 + new_pad + len*4 + pad_delta), | |
| 637 _overwrite, -pad_delta); | |
| 638 } else { | |
| 639 assert(pad_delta > 0, "check"); | |
| 640 // Move the expanded instruction up. | |
| 641 memmove(addr_at(bci +1 + new_pad), | |
| 642 addr_at(bci +1 + old_pad), | |
| 643 len * 4); | |
| 644 } | |
| 645 } | |
| 646 return true; | |
| 647 } |