1 /*
2 * Copyright (c) 1998, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "code/codeBlob.hpp"
27 #include "code/codeCache.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/scopeDesc.hpp"
30 #include "compiler/oopMap.hpp"
31 #include "gc_interface/collectedHeap.hpp"
32 #include "memory/allocation.inline.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "runtime/frame.inline.hpp"
35 #include "runtime/signature.hpp"
36 #ifdef COMPILER1
37 #include "c1/c1_Defs.hpp"
38 #endif
39 #ifdef COMPILER2
40 #include "opto/optoreg.hpp"
41 #endif
42
43 // OopMapStream
44
45 OopMapStream::OopMapStream(OopMap* oop_map) {
46 if(oop_map->omv_data() == NULL) {
47 _stream = new CompressedReadStream(oop_map->write_stream()->buffer());
48 } else {
49 _stream = new CompressedReadStream(oop_map->omv_data());
50 }
51 _mask = OopMapValue::type_mask_in_place;
52 _size = oop_map->omv_count();
53 _position = 0;
54 _valid_omv = false;
55 }
56
57
58 OopMapStream::OopMapStream(OopMap* oop_map, int oop_types_mask) {
59 if(oop_map->omv_data() == NULL) {
60 _stream = new CompressedReadStream(oop_map->write_stream()->buffer());
61 } else {
62 _stream = new CompressedReadStream(oop_map->omv_data());
63 }
64 _mask = oop_types_mask;
65 _size = oop_map->omv_count();
66 _position = 0;
67 _valid_omv = false;
68 }
69
70
71 void OopMapStream::find_next() {
72 while(_position++ < _size) {
73 _omv.read_from(_stream);
74 if(((int)_omv.type() & _mask) > 0) {
75 _valid_omv = true;
76 return;
77 }
78 }
79 _valid_omv = false;
80 }
81
82
83 // OopMap
84
85 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
86 // slots to hold 4-byte values like ints and floats in the LP64 build.
87 OopMap::OopMap(int frame_size, int arg_count) {
88 // OopMaps are usually quite so small, so pick a small initial size
89 set_write_stream(new CompressedWriteStream(32));
90 set_omv_data(NULL);
91 set_omv_count(0);
92
93 #ifdef ASSERT
94 _locs_length = VMRegImpl::stack2reg(0)->value() + frame_size + arg_count;
95 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
96 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
97 #endif
98 }
99
100
101 OopMap::OopMap(OopMap::DeepCopyToken, OopMap* source) {
102 // This constructor does a deep copy
103 // of the source OopMap.
104 set_write_stream(new CompressedWriteStream(source->omv_count() * 2));
105 set_omv_data(NULL);
106 set_omv_count(0);
107 set_offset(source->offset());
108
109 #ifdef ASSERT
110 _locs_length = source->_locs_length;
111 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
112 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
113 #endif
114
115 // We need to copy the entries too.
116 for (OopMapStream oms(source); !oms.is_done(); oms.next()) {
117 OopMapValue omv = oms.current();
118 omv.write_on(write_stream());
119 increment_count();
120 }
121 }
122
123
124 OopMap* OopMap::deep_copy() {
125 return new OopMap(_deep_copy_token, this);
126 }
127
128
129 void OopMap::copy_to(address addr) {
130 memcpy(addr,this,sizeof(OopMap));
131 memcpy(addr + sizeof(OopMap),write_stream()->buffer(),write_stream()->position());
132 OopMap* new_oop = (OopMap*)addr;
133 new_oop->set_omv_data_size(write_stream()->position());
134 new_oop->set_omv_data((unsigned char *)(addr + sizeof(OopMap)));
135 new_oop->set_write_stream(NULL);
136 }
137
138
139 int OopMap::heap_size() const {
140 int size = sizeof(OopMap);
141 int align = sizeof(void *) - 1;
142 if(write_stream() != NULL) {
143 size += write_stream()->position();
144 } else {
145 size += omv_data_size();
146 }
147 // Align to a reasonable ending point
148 size = ((size+align) & ~align);
149 return size;
150 }
151
152 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
153 // slots to hold 4-byte values like ints and floats in the LP64 build.
154 void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) {
155
156 assert(reg->value() < _locs_length, "too big reg value for stack size");
157 assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" );
158 debug_only( _locs_used[reg->value()] = x; )
159
160 OopMapValue o(reg, x);
161
162 if(x == OopMapValue::callee_saved_value) {
163 // This can never be a stack location, so we don't need to transform it.
164 assert(optional->is_reg(), "Trying to callee save a stack location");
165 o.set_content_reg(optional);
166 } else if(x == OopMapValue::derived_oop_value) {
167 o.set_content_reg(optional);
168 }
169
170 o.write_on(write_stream());
171 increment_count();
172 }
173
174
175 void OopMap::set_oop(VMReg reg) {
176 set_xxx(reg, OopMapValue::oop_value, VMRegImpl::Bad());
177 }
178
179
180 void OopMap::set_value(VMReg reg) {
181 // At this time, we only need value entries in our OopMap when ZapDeadCompiledLocals is active.
182 if (ZapDeadCompiledLocals)
183 set_xxx(reg, OopMapValue::value_value, VMRegImpl::Bad());
184 }
185
186
187 void OopMap::set_narrowoop(VMReg reg) {
188 set_xxx(reg, OopMapValue::narrowoop_value, VMRegImpl::Bad());
189 }
190
191
192 void OopMap::set_callee_saved(VMReg reg, VMReg caller_machine_register ) {
193 set_xxx(reg, OopMapValue::callee_saved_value, caller_machine_register);
194 }
195
196
197 void OopMap::set_derived_oop(VMReg reg, VMReg derived_from_local_register ) {
198 if( reg == derived_from_local_register ) {
199 // Actually an oop, derived shares storage with base,
200 set_oop(reg);
201 } else {
202 set_xxx(reg, OopMapValue::derived_oop_value, derived_from_local_register);
203 }
204 }
205
206 // OopMapSet
207
208 OopMapSet::OopMapSet() {
209 set_om_size(MinOopMapAllocation);
210 set_om_count(0);
211 OopMap** temp = NEW_RESOURCE_ARRAY(OopMap*, om_size());
212 set_om_data(temp);
213 }
214
215
216 void OopMapSet::grow_om_data() {
217 int new_size = om_size() * 2;
218 OopMap** new_data = NEW_RESOURCE_ARRAY(OopMap*, new_size);
219 memcpy(new_data,om_data(),om_size() * sizeof(OopMap*));
220 set_om_size(new_size);
221 set_om_data(new_data);
222 }
223
224
225 void OopMapSet::copy_to(address addr) {
226 address temp = addr;
227 int align = sizeof(void *) - 1;
228 // Copy this
229 memcpy(addr,this,sizeof(OopMapSet));
230 temp += sizeof(OopMapSet);
231 temp = (address)((intptr_t)(temp + align) & ~align);
232 // Do the needed fixups to the new OopMapSet
233 OopMapSet* new_set = (OopMapSet*)addr;
234 new_set->set_om_data((OopMap**)temp);
235 // Allow enough space for the OopMap pointers
236 temp += (om_count() * sizeof(OopMap*));
237
238 for(int i=0; i < om_count(); i++) {
239 OopMap* map = at(i);
240 map->copy_to((address)temp);
241 new_set->set(i,(OopMap*)temp);
242 temp += map->heap_size();
243 }
244 // This "locks" the OopMapSet
245 new_set->set_om_size(-1);
246 }
247
248
249 void OopMapSet::add_gc_map(int pc_offset, OopMap *map ) {
250 assert(om_size() != -1,"Cannot grow a fixed OopMapSet");
251
252 if(om_count() >= om_size()) {
253 grow_om_data();
254 }
255 map->set_offset(pc_offset);
256
257 #ifdef ASSERT
258 if(om_count() > 0) {
259 OopMap* last = at(om_count()-1);
260 if (last->offset() == map->offset() ) {
261 fatal("OopMap inserted twice");
262 }
263 if(last->offset() > map->offset()) {
264 tty->print_cr( "WARNING, maps not sorted: pc[%d]=%d, pc[%d]=%d",
265 om_count(),last->offset(),om_count()+1,map->offset());
266 }
267 }
268 #endif // ASSERT
269
270 set(om_count(),map);
271 increment_count();
272 }
273
274
275 int OopMapSet::heap_size() const {
276 // The space we use
277 int size = sizeof(OopMap);
278 int align = sizeof(void *) - 1;
279 size = ((size+align) & ~align);
280 size += om_count() * sizeof(OopMap*);
281
282 // Now add in the space needed for the indivdiual OopMaps
283 for(int i=0; i < om_count(); i++) {
284 size += at(i)->heap_size();
285 }
286 // We don't need to align this, it will be naturally pointer aligned
287 return size;
288 }
289
290
291 OopMap* OopMapSet::singular_oop_map() {
292 guarantee(om_count() == 1, "Make sure we only have a single gc point");
293 return at(0);
294 }
295
296
297 OopMap* OopMapSet::find_map_at_offset(int pc_offset) const {
298 int i, len = om_count();
299 assert( len > 0, "must have pointer maps" );
300
301 // Scan through oopmaps. Stop when current offset is either equal or greater
302 // than the one we are looking for.
303 for( i = 0; i < len; i++) {
304 if( at(i)->offset() >= pc_offset )
305 break;
306 }
307
308 assert( i < len, "oopmap not found" );
309
310 OopMap* m = at(i);
311 assert( m->offset() == pc_offset, "oopmap not found" );
312 return m;
313 }
314
315 class DoNothingClosure: public OopClosure {
316 public:
317 void do_oop(oop* p) {}
318 void do_oop(narrowOop* p) {}
319 };
320 static DoNothingClosure do_nothing;
321
322 static void add_derived_oop(oop* base, oop* derived) {
323 #ifndef TIERED
324 COMPILER1_PRESENT(ShouldNotReachHere();)
325 #endif // TIERED
326 #ifdef COMPILER2
327 DerivedPointerTable::add(derived, base);
328 #endif // COMPILER2
329 }
330
331
332 #ifndef PRODUCT
333 static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map) {
334 // Print oopmap and regmap
335 tty->print_cr("------ ");
336 CodeBlob* cb = fr->cb();
337 OopMapSet* maps = cb->oop_maps();
338 OopMap* map = cb->oop_map_for_return_address(fr->pc());
339 map->print();
340 if( cb->is_nmethod() ) {
341 nmethod* nm = (nmethod*)cb;
342 // native wrappers have no scope data, it is implied
343 if (nm->is_native_method()) {
344 tty->print("bci: 0 (native)");
345 } else {
346 ScopeDesc* scope = nm->scope_desc_at(fr->pc());
347 tty->print("bci: %d ",scope->bci());
348 }
349 }
350 tty->cr();
351 fr->print_on(tty);
352 tty->print(" ");
353 cb->print_value_on(tty); tty->cr();
354 reg_map->print();
355 tty->print_cr("------ ");
356
357 }
358 #endif // PRODUCT
359
360 void OopMapSet::oops_do(const frame *fr, const RegisterMap* reg_map, OopClosure* f) {
361 // add derived oops to a table
362 all_do(fr, reg_map, f, add_derived_oop, &do_nothing);
363 }
364
365
366 void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,
367 OopClosure* oop_fn, void derived_oop_fn(oop*, oop*),
368 OopClosure* value_fn) {
369 CodeBlob* cb = fr->cb();
370 assert(cb != NULL, "no codeblob");
371
372 NOT_PRODUCT(if (TraceCodeBlobStacks) trace_codeblob_maps(fr, reg_map);)
373
374 OopMapSet* maps = cb->oop_maps();
375 OopMap* map = cb->oop_map_for_return_address(fr->pc());
376 assert(map != NULL, "no ptr map found");
377
378 // handle derived pointers first (otherwise base pointer may be
379 // changed before derived pointer offset has been collected)
380 OopMapValue omv;
381 {
382 OopMapStream oms(map,OopMapValue::derived_oop_value);
383 if (!oms.is_done()) {
384 #ifndef TIERED
385 COMPILER1_PRESENT(ShouldNotReachHere();)
386 #endif // !TIERED
387 // Protect the operation on the derived pointers. This
388 // protects the addition of derived pointers to the shared
389 // derived pointer table in DerivedPointerTable::add().
390 MutexLockerEx x(DerivedPointerTableGC_lock, Mutex::_no_safepoint_check_flag);
391 do {
392 omv = oms.current();
393 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
394 if ( loc != NULL ) {
395 oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
396 oop *derived_loc = loc;
397 oop val = *base_loc;
398 if (val == (oop)NULL || Universe::is_narrow_oop_base(val)) {
399 // Ignore NULL oops and decoded NULL narrow oops which
400 // equal to Universe::narrow_oop_base when a narrow oop
401 // implicit null check is used in compiled code.
402 // The narrow_oop_base could be NULL or be the address
403 // of the page below heap depending on compressed oops mode.
404 } else
405 derived_oop_fn(base_loc, derived_loc);
406 }
407 oms.next();
408 } while (!oms.is_done());
409 }
410 }
411
412 // We want coop, value and oop oop_types
413 int mask = OopMapValue::oop_value | OopMapValue::value_value | OopMapValue::narrowoop_value;
414 {
415 for (OopMapStream oms(map,mask); !oms.is_done(); oms.next()) {
416 omv = oms.current();
417 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
418 if ( loc != NULL ) {
419 if ( omv.type() == OopMapValue::oop_value ) {
420 oop val = *loc;
421 if (val == (oop)NULL || Universe::is_narrow_oop_base(val)) {
422 // Ignore NULL oops and decoded NULL narrow oops which
423 // equal to Universe::narrow_oop_base when a narrow oop
424 // implicit null check is used in compiled code.
425 // The narrow_oop_base could be NULL or be the address
426 // of the page below heap depending on compressed oops mode.
427 continue;
428 }
429 #ifdef ASSERT
430 if ((((uintptr_t)loc & (sizeof(*loc)-1)) != 0) ||
431 !Universe::heap()->is_in_or_null(*loc)) {
432 tty->print_cr("# Found non oop pointer. Dumping state at failure");
433 // try to dump out some helpful debugging information
434 trace_codeblob_maps(fr, reg_map);
435 omv.print();
436 tty->print_cr("register r");
437 omv.reg()->print();
438 tty->print_cr("loc = %p *loc = %p\n", loc, (address)*loc);
439 // do the real assert.
440 assert(Universe::heap()->is_in_or_null(*loc), "found non oop pointer");
441 }
442 #endif // ASSERT
443 oop_fn->do_oop(loc);
444 } else if ( omv.type() == OopMapValue::value_value ) {
445 assert((*loc) == (oop)NULL || !Universe::is_narrow_oop_base(*loc),
446 "found invalid value pointer");
447 value_fn->do_oop(loc);
448 } else if ( omv.type() == OopMapValue::narrowoop_value ) {
449 narrowOop *nl = (narrowOop*)loc;
450 #ifndef VM_LITTLE_ENDIAN
451 if (!omv.reg()->is_stack()) {
452 // compressed oops in registers only take up 4 bytes of an
453 // 8 byte register but they are in the wrong part of the
454 // word so adjust loc to point at the right place.
455 nl = (narrowOop*)((address)nl + 4);
456 }
457 #endif
458 oop_fn->do_oop(nl);
459 }
460 }
461 }
462 }
463 }
464
465
466 // Update callee-saved register info for the following frame
467 void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {
468 ResourceMark rm;
469 CodeBlob* cb = fr->cb();
470 assert(cb != NULL, "no codeblob");
471
472 // Any reg might be saved by a safepoint handler (see generate_handler_blob).
473 assert( reg_map->_update_for_id == NULL || fr->is_older(reg_map->_update_for_id),
474 "already updated this map; do not 'update' it twice!" );
475 debug_only(reg_map->_update_for_id = fr->id());
476
477 // Check if caller must update oop argument
478 assert((reg_map->include_argument_oops() ||
479 !cb->caller_must_gc_arguments(reg_map->thread())),
480 "include_argument_oops should already be set");
481
482 // Scan through oopmap and find location of all callee-saved registers
483 // (we do not do update in place, since info could be overwritten)
484
485 address pc = fr->pc();
486 OopMap* map = cb->oop_map_for_return_address(pc);
487 assert(map != NULL, "no ptr map found");
488 DEBUG_ONLY(int nof_callee = 0;)
489
490 for (OopMapStream oms(map, OopMapValue::callee_saved_value); !oms.is_done(); oms.next()) {
491 OopMapValue omv = oms.current();
492 VMReg reg = omv.content_reg();
493 oop* loc = fr->oopmapreg_to_location(omv.reg(), reg_map);
494 reg_map->set_location(reg, (address) loc);
495 DEBUG_ONLY(nof_callee++;)
496 }
497
498 // Check that runtime stubs save all callee-saved registers
499 #ifdef COMPILER2
500 assert(cb->is_compiled_by_c1() || !cb->is_runtime_stub() ||
501 (nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT),
502 "must save all");
503 #endif // COMPILER2
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 st->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<mtCompiler> {
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, mtCompiler) 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 cast_from_oop<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 // This assert is invalid because derived pointers can be
632 // arbitrarily far away from their base.
633 // assert(offset >= -1000000, "wrong derived pointer info");
634
635 if (TraceDerivedPointers) {
636 tty->print_cr(
637 "Add derived pointer@" INTPTR_FORMAT
638 " - Derived: " INTPTR_FORMAT
639 " Base: " INTPTR_FORMAT " (@" INTPTR_FORMAT ") (Offset: " INTX_FORMAT ")",
640 p2i(derived_loc), p2i((address)*derived_loc), p2i((address)*base_loc), p2i(base_loc), offset
641 );
642 }
643 // Set derived oop location to point to base.
644 *derived_loc = (oop)base_loc;
645 assert_lock_strong(DerivedPointerTableGC_lock);
646 DerivedPointerEntry *entry = new DerivedPointerEntry(derived_loc, offset);
647 _list->append(entry);
648 }
649 }
650
651
652 void DerivedPointerTable::update_pointers() {
653 assert(_list != NULL, "list must exist");
654 for(int i = 0; i < _list->length(); i++) {
655 DerivedPointerEntry* entry = _list->at(i);
656 oop* derived_loc = entry->location();
657 intptr_t offset = entry->offset();
658 // The derived oop was setup to point to location of base
659 oop base = **(oop**)derived_loc;
660 assert(Universe::heap()->is_in_or_null(base), "must be an oop");
661
662 *derived_loc = (oop)(((address)base) + offset);
663 assert(value_of_loc(derived_loc) - value_of_loc(&base) == offset, "sanity check");
664
665 if (TraceDerivedPointers) {
666 tty->print_cr("Updating derived pointer@" INTPTR_FORMAT
667 " - Derived: " INTPTR_FORMAT " Base: " INTPTR_FORMAT " (Offset: " INTX_FORMAT ")",
668 p2i(derived_loc), p2i((address)*derived_loc), p2i((address)base), offset);
669 }
670
671 // Delete entry
672 delete entry;
673 _list->at_put(i, NULL);
674 }
675 // Clear list, so it is ready for next traversal (this is an invariant)
676 if (TraceDerivedPointers && !_list->is_empty()) {
677 tty->print_cr("--------------------------");
678 }
679 _list->clear();
680 _active = false;
681 }
682
683 #endif // COMPILER2