1 /* 2 * Copyright 1998-2008 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 */ 24 25 # include "incls/_precompiled.incl" 26 # include "incls/_oopMap.cpp.incl" 27 28 // OopMapStream 29 30 OopMapStream::OopMapStream(OopMap* oop_map) { 31 if(oop_map->omv_data() == NULL) { 32 _stream = new CompressedReadStream(oop_map->write_stream()->buffer()); 33 } else { 34 _stream = new CompressedReadStream(oop_map->omv_data()); 35 } 36 _mask = OopMapValue::type_mask_in_place; 37 _size = oop_map->omv_count(); 38 _position = 0; 39 _valid_omv = false; 40 } 41 42 43 OopMapStream::OopMapStream(OopMap* oop_map, int oop_types_mask) { 44 if(oop_map->omv_data() == NULL) { 45 _stream = new CompressedReadStream(oop_map->write_stream()->buffer()); 46 } else { 47 _stream = new CompressedReadStream(oop_map->omv_data()); 48 } 49 _mask = oop_types_mask; 50 _size = oop_map->omv_count(); 51 _position = 0; 52 _valid_omv = false; 53 } 54 55 56 void OopMapStream::find_next() { 57 while(_position++ < _size) { 58 _omv.read_from(_stream); 59 if(((int)_omv.type() & _mask) > 0) { 60 _valid_omv = true; 61 return; 62 } 63 } 64 _valid_omv = false; 65 } 66 67 68 // OopMap 69 70 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd 71 // slots to hold 4-byte values like ints and floats in the LP64 build. 72 OopMap::OopMap(int frame_size, int arg_count) { 73 // OopMaps are usually quite so small, so pick a small initial size 74 set_write_stream(new CompressedWriteStream(32)); 75 set_omv_data(NULL); 76 set_omv_count(0); 77 78 #ifdef ASSERT 79 _locs_length = VMRegImpl::stack2reg(0)->value() + frame_size + arg_count; 80 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length); 81 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value; 82 #endif 83 } 84 85 86 OopMap::OopMap(OopMap::DeepCopyToken, OopMap* source) { 87 // This constructor does a deep copy 88 // of the source OopMap. 89 set_write_stream(new CompressedWriteStream(source->omv_count() * 2)); 90 set_omv_data(NULL); 91 set_omv_count(0); 92 set_offset(source->offset()); 93 94 #ifdef ASSERT 95 _locs_length = source->_locs_length; 96 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length); 97 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value; 98 #endif 99 100 // We need to copy the entries too. 101 for (OopMapStream oms(source); !oms.is_done(); oms.next()) { 102 OopMapValue omv = oms.current(); 103 omv.write_on(write_stream()); 104 increment_count(); 105 } 106 } 107 108 109 OopMap* OopMap::deep_copy() { 110 return new OopMap(_deep_copy_token, this); 111 } 112 113 114 void OopMap::copy_to(address addr) { 115 memcpy(addr,this,sizeof(OopMap)); 116 memcpy(addr + sizeof(OopMap),write_stream()->buffer(),write_stream()->position()); 117 OopMap* new_oop = (OopMap*)addr; 118 new_oop->set_omv_data_size(write_stream()->position()); 119 new_oop->set_omv_data((unsigned char *)(addr + sizeof(OopMap))); 120 new_oop->set_write_stream(NULL); 121 } 122 123 124 int OopMap::heap_size() const { 125 int size = sizeof(OopMap); 126 int align = sizeof(void *) - 1; 127 if(write_stream() != NULL) { 128 size += write_stream()->position(); 129 } else { 130 size += omv_data_size(); 131 } 132 // Align to a reasonable ending point 133 size = ((size+align) & ~align); 134 return size; 135 } 136 137 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd 138 // slots to hold 4-byte values like ints and floats in the LP64 build. 139 void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) { 140 141 assert(reg->value() < _locs_length, "too big reg value for stack size"); 142 assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" ); 143 debug_only( _locs_used[reg->value()] = x; ) 144 145 OopMapValue o(reg, x); 146 147 if(x == OopMapValue::callee_saved_value) { 148 // This can never be a stack location, so we don't need to transform it. 149 assert(optional->is_reg(), "Trying to callee save a stack location"); 150 o.set_content_reg(optional); 151 } else if(x == OopMapValue::derived_oop_value) { 152 o.set_content_reg(optional); 153 } 154 155 o.write_on(write_stream()); 156 increment_count(); 157 } 158 159 160 void OopMap::set_oop(VMReg reg) { 161 set_xxx(reg, OopMapValue::oop_value, VMRegImpl::Bad()); 162 } 163 164 165 void OopMap::set_value(VMReg reg) { 166 // At this time, we only need value entries in our OopMap when ZapDeadCompiledLocals is active. 167 if (ZapDeadCompiledLocals) 168 set_xxx(reg, OopMapValue::value_value, VMRegImpl::Bad()); 169 } 170 171 172 void OopMap::set_narrowoop(VMReg reg) { 173 set_xxx(reg, OopMapValue::narrowoop_value, VMRegImpl::Bad()); 174 } 175 176 177 void OopMap::set_callee_saved(VMReg reg, VMReg caller_machine_register ) { 178 set_xxx(reg, OopMapValue::callee_saved_value, caller_machine_register); 179 } 180 181 182 void OopMap::set_derived_oop(VMReg reg, VMReg derived_from_local_register ) { 183 if( reg == derived_from_local_register ) { 184 // Actually an oop, derived shares storage with base, 185 set_oop(reg); 186 } else { 187 set_xxx(reg, OopMapValue::derived_oop_value, derived_from_local_register); 188 } 189 } 190 191 // OopMapSet 192 193 OopMapSet::OopMapSet() { 194 set_om_size(MinOopMapAllocation); 195 set_om_count(0); 196 OopMap** temp = NEW_RESOURCE_ARRAY(OopMap*, om_size()); 197 set_om_data(temp); 198 } 199 200 201 void OopMapSet::grow_om_data() { 202 int new_size = om_size() * 2; 203 OopMap** new_data = NEW_RESOURCE_ARRAY(OopMap*, new_size); 204 memcpy(new_data,om_data(),om_size() * sizeof(OopMap*)); 205 set_om_size(new_size); 206 set_om_data(new_data); 207 } 208 209 210 void OopMapSet::copy_to(address addr) { 211 address temp = addr; 212 int align = sizeof(void *) - 1; 213 // Copy this 214 memcpy(addr,this,sizeof(OopMapSet)); 215 temp += sizeof(OopMapSet); 216 temp = (address)((intptr_t)(temp + align) & ~align); 217 // Do the needed fixups to the new OopMapSet 218 OopMapSet* new_set = (OopMapSet*)addr; 219 new_set->set_om_data((OopMap**)temp); 220 // Allow enough space for the OopMap pointers 221 temp += (om_count() * sizeof(OopMap*)); 222 223 for(int i=0; i < om_count(); i++) { 224 OopMap* map = at(i); 225 map->copy_to((address)temp); 226 new_set->set(i,(OopMap*)temp); 227 temp += map->heap_size(); 228 } 229 // This "locks" the OopMapSet 230 new_set->set_om_size(-1); 231 } 232 233 234 void OopMapSet::add_gc_map(int pc_offset, OopMap *map ) { 235 assert(om_size() != -1,"Cannot grow a fixed OopMapSet"); 236 237 if(om_count() >= om_size()) { 238 grow_om_data(); 239 } 240 map->set_offset(pc_offset); 241 242 #ifdef ASSERT 243 if(om_count() > 0) { 244 OopMap* last = at(om_count()-1); 245 if (last->offset() == map->offset() ) { 246 fatal("OopMap inserted twice"); 247 } 248 if(last->offset() > map->offset()) { 249 tty->print_cr( "WARNING, maps not sorted: pc[%d]=%d, pc[%d]=%d", 250 om_count(),last->offset(),om_count()+1,map->offset()); 251 } 252 } 253 #endif // ASSERT 254 255 set(om_count(),map); 256 increment_count(); 257 } 258 259 260 int OopMapSet::heap_size() const { 261 // The space we use 262 int size = sizeof(OopMap); 263 int align = sizeof(void *) - 1; 264 size = ((size+align) & ~align); 265 size += om_count() * sizeof(OopMap*); 266 267 // Now add in the space needed for the indivdiual OopMaps 268 for(int i=0; i < om_count(); i++) { 269 size += at(i)->heap_size(); 270 } 271 // We don't need to align this, it will be naturally pointer aligned 272 return size; 273 } 274 275 276 OopMap* OopMapSet::singular_oop_map() { 277 guarantee(om_count() == 1, "Make sure we only have a single gc point"); 278 return at(0); 279 } 280 281 282 OopMap* OopMapSet::find_map_at_offset(int pc_offset) const { 283 int i, len = om_count(); 284 assert( len > 0, "must have pointer maps" ); 285 286 // Scan through oopmaps. Stop when current offset is either equal or greater 287 // than the one we are looking for. 288 for( i = 0; i < len; i++) { 289 if( at(i)->offset() >= pc_offset ) 290 break; 291 } 292 293 assert( i < len, "oopmap not found" ); 294 295 OopMap* m = at(i); 296 assert( m->offset() == pc_offset, "oopmap not found" ); 297 return m; 298 } 299 300 class DoNothingClosure: public OopClosure { 301 public: 302 void do_oop(oop* p) {} 303 void do_oop(narrowOop* p) {} 304 }; 305 static DoNothingClosure do_nothing; 306 307 static void add_derived_oop(oop* base, oop* derived) { 308 #ifndef TIERED 309 COMPILER1_PRESENT(ShouldNotReachHere();) 310 #endif // TIERED 311 #ifdef COMPILER2 312 DerivedPointerTable::add(derived, base); 313 #endif // COMPILER2 314 } 315 316 317 #ifndef PRODUCT 318 static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map) { 319 // Print oopmap and regmap 320 tty->print_cr("------ "); 321 CodeBlob* cb = fr->cb(); 322 OopMapSet* maps = cb->oop_maps(); 323 OopMap* map = cb->oop_map_for_return_address(fr->pc()); 324 map->print(); 325 if( cb->is_nmethod() ) { 326 nmethod* nm = (nmethod*)cb; 327 // native wrappers have no scope data, it is implied 328 if (nm->is_native_method()) { 329 tty->print("bci: 0 (native)"); 330 } else { 331 ScopeDesc* scope = nm->scope_desc_at(fr->pc()); 332 tty->print("bci: %d ",scope->bci()); 333 } 334 } 335 tty->cr(); 336 fr->print_on(tty); 337 tty->print(" "); 338 cb->print_value_on(tty); tty->cr(); 339 reg_map->print(); 340 tty->print_cr("------ "); 341 342 } 343 #endif // PRODUCT 344 345 void OopMapSet::oops_do(const frame *fr, const RegisterMap* reg_map, OopClosure* f) { 346 // add derived oops to a table 347 all_do(fr, reg_map, f, add_derived_oop, &do_nothing); 348 } 349 350 351 void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map, 352 OopClosure* oop_fn, void derived_oop_fn(oop*, oop*), 353 OopClosure* value_fn) { 354 CodeBlob* cb = fr->cb(); 355 assert(cb != NULL, "no codeblob"); 356 357 NOT_PRODUCT(if (TraceCodeBlobStacks) trace_codeblob_maps(fr, reg_map);) 358 359 OopMapSet* maps = cb->oop_maps(); 360 OopMap* map = cb->oop_map_for_return_address(fr->pc()); 361 assert(map != NULL, "no ptr map found"); 362 363 // handle derived pointers first (otherwise base pointer may be 364 // changed before derived pointer offset has been collected) 365 OopMapValue omv; 366 { 367 OopMapStream oms(map,OopMapValue::derived_oop_value); 368 if (!oms.is_done()) { 369 #ifndef TIERED 370 COMPILER1_PRESENT(ShouldNotReachHere();) 371 #endif // !TIERED 372 // Protect the operation on the derived pointers. This 373 // protects the addition of derived pointers to the shared 374 // derived pointer table in DerivedPointerTable::add(). 375 MutexLockerEx x(DerivedPointerTableGC_lock, Mutex::_no_safepoint_check_flag); 376 do { 377 omv = oms.current(); 378 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map); 379 if ( loc != NULL ) { 380 oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map); 381 oop *derived_loc = loc; 382 #ifdef _LP64 383 if (Universe::narrow_oop_base() == (address)(void*)(*base_loc)) { 384 // Compiled code may produce decoded oop = narrow_oop_base 385 // when a narrow oop implicit null check is used. 386 // The narrow_oop_base could be NULL or be the address 387 // of the page below heap. Skip both cases since nobody 388 // is interesting in NULL. 389 } else 390 #endif 391 derived_oop_fn(base_loc, derived_loc); 392 } 393 oms.next(); 394 } while (!oms.is_done()); 395 } 396 } 397 398 // We want coop, value and oop oop_types 399 int mask = OopMapValue::oop_value | OopMapValue::value_value | OopMapValue::narrowoop_value; 400 { 401 for (OopMapStream oms(map,mask); !oms.is_done(); oms.next()) { 402 omv = oms.current(); 403 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map); 404 if ( loc != NULL ) { 405 if ( omv.type() == OopMapValue::oop_value ) { 406 #ifdef _LP64 407 if (Universe::narrow_oop_base() == (address)(void*)(*loc)) { 408 // Compiled code may produce decoded oop = narrow_oop_base 409 // when a narrow oop implicit null check is used. 410 // The narrow_oop_base could be NULL or be the address 411 // of the page below heap. Skip both cases since nobody 412 // is interesting in NULL. 413 continue; 414 } 415 #endif 416 #ifdef ASSERT 417 if ((((uintptr_t)loc & (sizeof(*loc)-1)) != 0) || 418 !Universe::heap()->is_in_or_null(*loc)) { 419 tty->print_cr("# Found non oop pointer. Dumping state at failure"); 420 // try to dump out some helpful debugging information 421 trace_codeblob_maps(fr, reg_map); 422 omv.print(); 423 tty->print_cr("register r"); 424 omv.reg()->print(); 425 tty->print_cr("loc = %p *loc = %p\n", loc, (address)*loc); 426 // do the real assert. 427 assert(Universe::heap()->is_in_or_null(*loc), "found non oop pointer"); 428 } 429 #endif // ASSERT 430 oop_fn->do_oop(loc); 431 } else if ( omv.type() == OopMapValue::value_value ) { 432 assert((*loc) == (oop)NULL || Universe::narrow_oop_base() != (address)(void*)(*loc), 433 "found non valid value pointer"); 434 value_fn->do_oop(loc); 435 } else if ( omv.type() == OopMapValue::narrowoop_value ) { 436 narrowOop *nl = (narrowOop*)loc; 437 #ifndef VM_LITTLE_ENDIAN 438 if (!omv.reg()->is_stack()) { 439 // compressed oops in registers only take up 4 bytes of an 440 // 8 byte register but they are in the wrong part of the 441 // word so adjust loc to point at the right place. 442 nl = (narrowOop*)((address)nl + 4); 443 } 444 #endif 445 oop_fn->do_oop(nl); 446 } 447 } 448 } 449 } 450 } 451 452 453 // Update callee-saved register info for the following frame 454 void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) { 455 ResourceMark rm; 456 CodeBlob* cb = fr->cb(); 457 assert(cb != NULL, "no codeblob"); 458 459 // Any reg might be saved by a safepoint handler (see generate_handler_blob). 460 const int max_saved_on_entry_reg_count = ConcreteRegisterImpl::number_of_registers; 461 assert( reg_map->_update_for_id == NULL || fr->is_older(reg_map->_update_for_id), 462 "already updated this map; do not 'update' it twice!" ); 463 debug_only(reg_map->_update_for_id = fr->id()); 464 465 // Check if caller must update oop argument 466 assert((reg_map->include_argument_oops() || 467 !cb->caller_must_gc_arguments(reg_map->thread())), 468 "include_argument_oops should already be set"); 469 470 int nof_callee = 0; 471 oop* locs[2*max_saved_on_entry_reg_count+1]; 472 VMReg regs[2*max_saved_on_entry_reg_count+1]; 473 // ("+1" because max_saved_on_entry_reg_count might be zero) 474 475 // Scan through oopmap and find location of all callee-saved registers 476 // (we do not do update in place, since info could be overwritten) 477 478 address pc = fr->pc(); 479 480 OopMap* map = cb->oop_map_for_return_address(pc); 481 482 assert(map != NULL, " no ptr map found"); 483 484 OopMapValue omv; 485 for(OopMapStream oms(map,OopMapValue::callee_saved_value); !oms.is_done(); oms.next()) { 486 omv = oms.current(); 487 assert(nof_callee < 2*max_saved_on_entry_reg_count, "overflow"); 488 regs[nof_callee] = omv.content_reg(); 489 locs[nof_callee] = fr->oopmapreg_to_location(omv.reg(),reg_map); 490 nof_callee++; 491 } 492 493 // Check that runtime stubs save all callee-saved registers 494 #ifdef COMPILER2 495 assert(cb->is_compiled_by_c1() || !cb->is_runtime_stub() || 496 (nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT), 497 "must save all"); 498 #endif // COMPILER2 499 500 // Copy found callee-saved register to reg_map 501 for(int i = 0; i < nof_callee; i++) { 502 reg_map->set_location(regs[i], (address)locs[i]); 503 } 504 } 505 506 //============================================================================= 507 // Non-Product code 508 509 #ifndef PRODUCT 510 511 bool OopMap::has_derived_pointer() const { 512 #ifndef TIERED 513 COMPILER1_PRESENT(return false); 514 #endif // !TIERED 515 #ifdef COMPILER2 516 OopMapStream oms((OopMap*)this,OopMapValue::derived_oop_value); 517 return oms.is_done(); 518 #else 519 return false; 520 #endif // COMPILER2 521 } 522 523 #endif //PRODUCT 524 525 // Printing code is present in product build for -XX:+PrintAssembly. 526 527 static 528 void print_register_type(OopMapValue::oop_types x, VMReg optional, 529 outputStream* st) { 530 switch( x ) { 531 case OopMapValue::oop_value: 532 st->print("Oop"); 533 break; 534 case OopMapValue::value_value: 535 st->print("Value" ); 536 break; 537 case OopMapValue::narrowoop_value: 538 tty->print("NarrowOop" ); 539 break; 540 case OopMapValue::callee_saved_value: 541 st->print("Callers_" ); 542 optional->print_on(st); 543 break; 544 case OopMapValue::derived_oop_value: 545 st->print("Derived_oop_" ); 546 optional->print_on(st); 547 break; 548 default: 549 ShouldNotReachHere(); 550 } 551 } 552 553 554 void OopMapValue::print_on(outputStream* st) const { 555 reg()->print_on(st); 556 st->print("="); 557 print_register_type(type(),content_reg(),st); 558 st->print(" "); 559 } 560 561 562 void OopMap::print_on(outputStream* st) const { 563 OopMapValue omv; 564 st->print("OopMap{"); 565 for(OopMapStream oms((OopMap*)this); !oms.is_done(); oms.next()) { 566 omv = oms.current(); 567 omv.print_on(st); 568 } 569 st->print("off=%d}", (int) offset()); 570 } 571 572 573 void OopMapSet::print_on(outputStream* st) const { 574 int i, len = om_count(); 575 576 st->print_cr("OopMapSet contains %d OopMaps\n",len); 577 578 for( i = 0; i < len; i++) { 579 OopMap* m = at(i); 580 st->print_cr("#%d ",i); 581 m->print_on(st); 582 st->cr(); 583 } 584 } 585 586 587 588 //------------------------------DerivedPointerTable--------------------------- 589 590 #ifdef COMPILER2 591 592 class DerivedPointerEntry : public CHeapObj { 593 private: 594 oop* _location; // Location of derived pointer (also pointing to the base) 595 intptr_t _offset; // Offset from base pointer 596 public: 597 DerivedPointerEntry(oop* location, intptr_t offset) { _location = location; _offset = offset; } 598 oop* location() { return _location; } 599 intptr_t offset() { return _offset; } 600 }; 601 602 603 GrowableArray<DerivedPointerEntry*>* DerivedPointerTable::_list = NULL; 604 bool DerivedPointerTable::_active = false; 605 606 607 void DerivedPointerTable::clear() { 608 // The first time, we create the list. Otherwise it should be 609 // empty. If not, then we have probably forgotton to call 610 // update_pointers after last GC/Scavenge. 611 assert (!_active, "should not be active"); 612 assert(_list == NULL || _list->length() == 0, "table not empty"); 613 if (_list == NULL) { 614 _list = new (ResourceObj::C_HEAP) GrowableArray<DerivedPointerEntry*>(10, true); // Allocated on C heap 615 } 616 _active = true; 617 } 618 619 620 // Returns value of location as an int 621 intptr_t value_of_loc(oop *pointer) { return (intptr_t)(*pointer); } 622 623 624 void DerivedPointerTable::add(oop *derived_loc, oop *base_loc) { 625 assert(Universe::heap()->is_in_or_null(*base_loc), "not an oop"); 626 assert(derived_loc != base_loc, "Base and derived in same location"); 627 if (_active) { 628 assert(*derived_loc != (oop)base_loc, "location already added"); 629 assert(_list != NULL, "list must exist"); 630 intptr_t offset = value_of_loc(derived_loc) - value_of_loc(base_loc); 631 assert(offset >= -1000000, "wrong derived pointer info"); 632 633 if (TraceDerivedPointers) { 634 tty->print_cr( 635 "Add derived pointer@" INTPTR_FORMAT 636 " - Derived: " INTPTR_FORMAT 637 " Base: " INTPTR_FORMAT " (@" INTPTR_FORMAT ") (Offset: %d)", 638 derived_loc, (address)*derived_loc, (address)*base_loc, base_loc, offset 639 ); 640 } 641 // Set derived oop location to point to base. 642 *derived_loc = (oop)base_loc; 643 assert_lock_strong(DerivedPointerTableGC_lock); 644 DerivedPointerEntry *entry = new DerivedPointerEntry(derived_loc, offset); 645 _list->append(entry); 646 } 647 } 648 649 650 void DerivedPointerTable::update_pointers() { 651 assert(_list != NULL, "list must exist"); 652 for(int i = 0; i < _list->length(); i++) { 653 DerivedPointerEntry* entry = _list->at(i); 654 oop* derived_loc = entry->location(); 655 intptr_t offset = entry->offset(); 656 // The derived oop was setup to point to location of base 657 oop base = **(oop**)derived_loc; 658 assert(Universe::heap()->is_in_or_null(base), "must be an oop"); 659 660 *derived_loc = (oop)(((address)base) + offset); 661 assert(value_of_loc(derived_loc) - value_of_loc(&base) == offset, "sanity check"); 662 663 if (TraceDerivedPointers) { 664 tty->print_cr("Updating derived pointer@" INTPTR_FORMAT 665 " - Derived: " INTPTR_FORMAT " Base: " INTPTR_FORMAT " (Offset: %d)", 666 derived_loc, (address)*derived_loc, (address)base, offset); 667 } 668 669 // Delete entry 670 delete entry; 671 _list->at_put(i, NULL); 672 } 673 // Clear list, so it is ready for next traversal (this is an invariant) 674 if (TraceDerivedPointers && !_list->is_empty()) { 675 tty->print_cr("--------------------------"); 676 } 677 _list->clear(); 678 _active = false; 679 } 680 681 #endif // COMPILER2