1 /*
2 * Copyright (c) 1998, 2019, 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/shared/collectedHeap.hpp"
32 #include "memory/allocation.inline.hpp"
33 #include "memory/iterator.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "memory/universe.hpp"
36 #include "oops/compressedOops.hpp"
37 #include "runtime/frame.inline.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "runtime/signature.hpp"
40 #include "utilities/align.hpp"
41 #include "utilities/lockFreeStack.hpp"
42 #ifdef COMPILER1
43 #include "c1/c1_Defs.hpp"
44 #endif
45 #ifdef COMPILER2
46 #include "opto/optoreg.hpp"
47 #endif
48
49 // OopMapStream
50
51 OopMapStream::OopMapStream(OopMap* oop_map) {
52 _stream = new CompressedReadStream(oop_map->write_stream()->buffer());
53 _size = oop_map->omv_count();
54 _position = 0;
55 _valid_omv = false;
56 }
57
58 OopMapStream::OopMapStream(const ImmutableOopMap* oop_map) {
59 _stream = new CompressedReadStream(oop_map->data_addr());
60 _size = oop_map->count();
61 _position = 0;
62 _valid_omv = false;
63 }
64
65 void OopMapStream::find_next() {
66 if (_position++ < _size) {
67 _omv.read_from(_stream);
68 _valid_omv = true;
69 return;
70 }
71 _valid_omv = false;
72 }
73
74
75 // OopMap
76
77 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
78 // slots to hold 4-byte values like ints and floats in the LP64 build.
79 OopMap::OopMap(int frame_size, int arg_count) {
80 // OopMaps are usually quite so small, so pick a small initial size
81 set_write_stream(new CompressedWriteStream(32));
82 set_omv_count(0);
83
84 #ifdef ASSERT
85 _locs_length = VMRegImpl::stack2reg(0)->value() + frame_size + arg_count;
86 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
87 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
88 #endif
89 }
90
91
92 OopMap::OopMap(OopMap::DeepCopyToken, OopMap* source) {
93 // This constructor does a deep copy
94 // of the source OopMap.
95 set_write_stream(new CompressedWriteStream(source->omv_count() * 2));
96 set_omv_count(0);
97 set_offset(source->offset());
98
99 #ifdef ASSERT
100 _locs_length = source->_locs_length;
101 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
102 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
103 #endif
104
105 // We need to copy the entries too.
106 for (OopMapStream oms(source); !oms.is_done(); oms.next()) {
107 OopMapValue omv = oms.current();
108 omv.write_on(write_stream());
109 increment_count();
110 }
111 }
112
113
114 OopMap* OopMap::deep_copy() {
115 return new OopMap(_deep_copy_token, this);
116 }
117
118 void OopMap::copy_data_to(address addr) const {
119 memcpy(addr, write_stream()->buffer(), write_stream()->position());
120 }
121
122 int OopMap::heap_size() const {
123 int size = sizeof(OopMap);
124 int align = sizeof(void *) - 1;
125 size += write_stream()->position();
126 // Align to a reasonable ending point
127 size = ((size+align) & ~align);
128 return size;
129 }
130
131 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
132 // slots to hold 4-byte values like ints and floats in the LP64 build.
133 void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) {
134
135 assert(reg->value() < _locs_length, "too big reg value for stack size");
136 assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" );
137 debug_only( _locs_used[reg->value()] = x; )
138
139 OopMapValue o(reg, x, optional);
140 o.write_on(write_stream());
141 increment_count();
142 }
143
144
145 void OopMap::set_oop(VMReg reg) {
146 set_xxx(reg, OopMapValue::oop_value, VMRegImpl::Bad());
147 }
148
149
150 void OopMap::set_narrowoop(VMReg reg) {
151 set_xxx(reg, OopMapValue::narrowoop_value, VMRegImpl::Bad());
152 }
153
154
155 void OopMap::set_callee_saved(VMReg reg, VMReg caller_machine_register ) {
156 set_xxx(reg, OopMapValue::callee_saved_value, caller_machine_register);
157 }
158
159
160 void OopMap::set_derived_oop(VMReg reg, VMReg derived_from_local_register ) {
161 if( reg == derived_from_local_register ) {
162 // Actually an oop, derived shares storage with base,
163 set_oop(reg);
164 } else {
165 set_xxx(reg, OopMapValue::derived_oop_value, derived_from_local_register);
166 }
167 }
168
169 // OopMapSet
170
171 OopMapSet::OopMapSet() : _list(MinOopMapAllocation) {}
172
173 void OopMapSet::add_gc_map(int pc_offset, OopMap *map ) {
174 map->set_offset(pc_offset);
175
176 #ifdef ASSERT
177 if(_list.length() > 0) {
178 OopMap* last = _list.last();
179 if (last->offset() == map->offset() ) {
180 fatal("OopMap inserted twice");
181 }
182 if (last->offset() > map->offset()) {
183 tty->print_cr( "WARNING, maps not sorted: pc[%d]=%d, pc[%d]=%d",
184 _list.length(),last->offset(),_list.length()+1,map->offset());
185 }
186 }
187 #endif // ASSERT
188
189 add(map);
190 }
191
192 static void add_derived_oop(oop* base, oop* derived) {
193 #if !defined(TIERED) && !INCLUDE_JVMCI
194 COMPILER1_PRESENT(ShouldNotReachHere();)
195 #endif // !defined(TIERED) && !INCLUDE_JVMCI
196 #if COMPILER2_OR_JVMCI
197 DerivedPointerTable::add(derived, base);
198 #endif // COMPILER2_OR_JVMCI
199 }
200
201
202 #ifndef PRODUCT
203 static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map) {
204 // Print oopmap and regmap
205 tty->print_cr("------ ");
206 CodeBlob* cb = fr->cb();
207 const ImmutableOopMapSet* maps = cb->oop_maps();
208 const ImmutableOopMap* map = cb->oop_map_for_return_address(fr->pc());
209 map->print();
210 if( cb->is_nmethod() ) {
211 nmethod* nm = (nmethod*)cb;
212 // native wrappers have no scope data, it is implied
213 if (nm->is_native_method()) {
214 tty->print("bci: 0 (native)");
215 } else {
216 ScopeDesc* scope = nm->scope_desc_at(fr->pc());
217 tty->print("bci: %d ",scope->bci());
218 }
219 }
220 tty->cr();
221 fr->print_on(tty);
222 tty->print(" ");
223 cb->print_value_on(tty); tty->cr();
224 reg_map->print();
225 tty->print_cr("------ ");
226
227 }
228 #endif // PRODUCT
229
230 void OopMapSet::oops_do(const frame *fr, const RegisterMap* reg_map, OopClosure* f) {
231 // add derived oops to a table
232 all_do(fr, reg_map, f, add_derived_oop, &do_nothing_cl);
233 }
234
235
236 void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,
237 OopClosure* oop_fn, void derived_oop_fn(oop*, oop*),
238 OopClosure* value_fn) {
239 CodeBlob* cb = fr->cb();
240 assert(cb != NULL, "no codeblob");
241
242 NOT_PRODUCT(if (TraceCodeBlobStacks) trace_codeblob_maps(fr, reg_map);)
243
244 const ImmutableOopMap* map = cb->oop_map_for_return_address(fr->pc());
245 assert(map != NULL, "no ptr map found");
246
247 // handle derived pointers first (otherwise base pointer may be
248 // changed before derived pointer offset has been collected)
249 {
250 for (OopMapStream oms(map); !oms.is_done(); oms.next()) {
251 OopMapValue omv = oms.current();
252 if (omv.type() != OopMapValue::derived_oop_value) {
253 continue;
254 }
255
256 #ifndef TIERED
257 COMPILER1_PRESENT(ShouldNotReachHere();)
258 #if INCLUDE_JVMCI
259 if (UseJVMCICompiler) {
260 ShouldNotReachHere();
261 }
262 #endif
263 #endif // !TIERED
264 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
265 guarantee(loc != NULL, "missing saved register");
266 oop *derived_loc = loc;
267 oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
268 // Ignore NULL oops and decoded NULL narrow oops which
269 // equal to CompressedOops::base() when a narrow oop
270 // implicit null check is used in compiled code.
271 // The narrow_oop_base could be NULL or be the address
272 // of the page below heap depending on compressed oops mode.
273 if (base_loc != NULL && *base_loc != NULL && !CompressedOops::is_base(*base_loc)) {
274 derived_oop_fn(base_loc, derived_loc);
275 }
276 }
277 }
278
279 {
280 // We want coop and oop oop_types
281 for (OopMapStream oms(map); !oms.is_done(); oms.next()) {
282 OopMapValue omv = oms.current();
283 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
284 // It should be an error if no location can be found for a
285 // register mentioned as contained an oop of some kind. Maybe
286 // this was allowed previously because value_value items might
287 // be missing?
288 guarantee(loc != NULL, "missing saved register");
289 if ( omv.type() == OopMapValue::oop_value ) {
290 oop val = *loc;
291 if (val == NULL || CompressedOops::is_base(val)) {
292 // Ignore NULL oops and decoded NULL narrow oops which
293 // equal to CompressedOops::base() when a narrow oop
294 // implicit null check is used in compiled code.
295 // The narrow_oop_base could be NULL or be the address
296 // of the page below heap depending on compressed oops mode.
297 continue;
298 }
299 #ifdef ASSERT
300 if ((((uintptr_t)loc & (sizeof(*loc)-1)) != 0) ||
301 !Universe::heap()->is_in_or_null(*loc)) {
302 tty->print_cr("# Found non oop pointer. Dumping state at failure");
303 // try to dump out some helpful debugging information
304 trace_codeblob_maps(fr, reg_map);
305 omv.print();
306 tty->print_cr("register r");
307 omv.reg()->print();
308 tty->print_cr("loc = %p *loc = %p\n", loc, cast_from_oop<address>(*loc));
309 // do the real assert.
310 assert(Universe::heap()->is_in_or_null(*loc), "found non oop pointer");
311 }
312 #endif // ASSERT
313 oop_fn->do_oop(loc);
314 } else if ( omv.type() == OopMapValue::narrowoop_value ) {
315 narrowOop *nl = (narrowOop*)loc;
316 #ifndef VM_LITTLE_ENDIAN
317 VMReg vmReg = omv.reg();
318 if (!vmReg->is_stack()) {
319 // compressed oops in registers only take up 4 bytes of an
320 // 8 byte register but they are in the wrong part of the
321 // word so adjust loc to point at the right place.
322 nl = (narrowOop*)((address)nl + 4);
323 }
324 #endif
325 oop_fn->do_oop(nl);
326 }
327 }
328 }
329 }
330
331
332 // Update callee-saved register info for the following frame
333 void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {
334 ResourceMark rm;
335 CodeBlob* cb = fr->cb();
336 assert(cb != NULL, "no codeblob");
337
338 // Any reg might be saved by a safepoint handler (see generate_handler_blob).
339 assert( reg_map->_update_for_id == NULL || fr->is_older(reg_map->_update_for_id),
340 "already updated this map; do not 'update' it twice!" );
341 debug_only(reg_map->_update_for_id = fr->id());
342
343 // Check if caller must update oop argument
344 assert((reg_map->include_argument_oops() ||
345 !cb->caller_must_gc_arguments(reg_map->thread())),
346 "include_argument_oops should already be set");
347
348 // Scan through oopmap and find location of all callee-saved registers
349 // (we do not do update in place, since info could be overwritten)
350
351 address pc = fr->pc();
352 const ImmutableOopMap* map = cb->oop_map_for_return_address(pc);
353 assert(map != NULL, "no ptr map found");
354 DEBUG_ONLY(int nof_callee = 0;)
355
356 for (OopMapStream oms(map); !oms.is_done(); oms.next()) {
357 OopMapValue omv = oms.current();
358 if (omv.type() == OopMapValue::callee_saved_value) {
359 VMReg reg = omv.content_reg();
360 oop* loc = fr->oopmapreg_to_location(omv.reg(), reg_map);
361 reg_map->set_location(reg, (address) loc);
362 DEBUG_ONLY(nof_callee++;)
363 }
364 }
365
366 // Check that runtime stubs save all callee-saved registers
367 #ifdef COMPILER2
368 assert(cb->is_compiled_by_c1() || cb->is_compiled_by_jvmci() || !cb->is_runtime_stub() ||
369 (nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT),
370 "must save all");
371 #endif // COMPILER2
372 }
373
374 // Printing code is present in product build for -XX:+PrintAssembly.
375
376 static
377 void print_register_type(OopMapValue::oop_types x, VMReg optional,
378 outputStream* st) {
379 switch( x ) {
380 case OopMapValue::oop_value:
381 st->print("Oop");
382 break;
383 case OopMapValue::narrowoop_value:
384 st->print("NarrowOop");
385 break;
386 case OopMapValue::callee_saved_value:
387 st->print("Callers_");
388 optional->print_on(st);
389 break;
390 case OopMapValue::derived_oop_value:
391 st->print("Derived_oop_");
392 optional->print_on(st);
393 break;
394 default:
395 ShouldNotReachHere();
396 }
397 }
398
399 void OopMapValue::print_on(outputStream* st) const {
400 reg()->print_on(st);
401 st->print("=");
402 print_register_type(type(),content_reg(),st);
403 st->print(" ");
404 }
405
406 void OopMapValue::print() const { print_on(tty); }
407
408 void ImmutableOopMap::print_on(outputStream* st) const {
409 OopMapValue omv;
410 st->print("ImmutableOopMap {");
411 for(OopMapStream oms(this); !oms.is_done(); oms.next()) {
412 omv = oms.current();
413 omv.print_on(st);
414 }
415 st->print("}");
416 }
417
418 void ImmutableOopMap::print() const { print_on(tty); }
419
420 void OopMap::print_on(outputStream* st) const {
421 OopMapValue omv;
422 st->print("OopMap {");
423 for(OopMapStream oms((OopMap*)this); !oms.is_done(); oms.next()) {
424 omv = oms.current();
425 omv.print_on(st);
426 }
427 // Print hex offset in addition.
428 st->print("off=%d/0x%x}", (int) offset(), (int) offset());
429 }
430
431 void OopMap::print() const { print_on(tty); }
432
433 void ImmutableOopMapSet::print_on(outputStream* st) const {
434 const ImmutableOopMap* last = NULL;
435 const int len = count();
436
437 st->print_cr("ImmutableOopMapSet contains %d OopMaps", len);
438
439 for (int i = 0; i < len; i++) {
440 const ImmutableOopMapPair* pair = pair_at(i);
441 const ImmutableOopMap* map = pair->get_from(this);
442 if (map != last) {
443 st->cr();
444 map->print_on(st);
445 st->print(" pc offsets: ");
446 }
447 last = map;
448 st->print("%d ", pair->pc_offset());
449 }
450 st->cr();
451 }
452
453 void ImmutableOopMapSet::print() const { print_on(tty); }
454
455 void OopMapSet::print_on(outputStream* st) const {
456 const int len = _list.length();
457
458 st->print_cr("OopMapSet contains %d OopMaps", len);
459
460 for( int i = 0; i < len; i++) {
461 OopMap* m = at(i);
462 st->print_cr("#%d ",i);
463 m->print_on(st);
464 st->cr();
465 }
466 st->cr();
467 }
468
469 void OopMapSet::print() const { print_on(tty); }
470
471 bool OopMap::equals(const OopMap* other) const {
472 if (other->_omv_count != _omv_count) {
473 return false;
474 }
475 if (other->write_stream()->position() != write_stream()->position()) {
476 return false;
477 }
478 if (memcmp(other->write_stream()->buffer(), write_stream()->buffer(), write_stream()->position()) != 0) {
479 return false;
480 }
481 return true;
482 }
483
484 const ImmutableOopMap* ImmutableOopMapSet::find_map_at_offset(int pc_offset) const {
485 ImmutableOopMapPair* pairs = get_pairs();
486 ImmutableOopMapPair* last = NULL;
487
488 for (int i = 0; i < _count; ++i) {
489 if (pairs[i].pc_offset() >= pc_offset) {
490 last = &pairs[i];
491 break;
492 }
493 }
494
495 // Heal Coverity issue: potential index out of bounds access.
496 guarantee(last != NULL, "last may not be null");
497 assert(last->pc_offset() == pc_offset, "oopmap not found");
498 return last->get_from(this);
499 }
500
501 const ImmutableOopMap* ImmutableOopMapPair::get_from(const ImmutableOopMapSet* set) const {
502 return set->oopmap_at_offset(_oopmap_offset);
503 }
504
505 ImmutableOopMap::ImmutableOopMap(const OopMap* oopmap) : _count(oopmap->count()) {
506 address addr = data_addr();
507 oopmap->copy_data_to(addr);
508 }
509
510 #ifdef ASSERT
511 int ImmutableOopMap::nr_of_bytes() const {
512 OopMapStream oms(this);
513
514 while (!oms.is_done()) {
515 oms.next();
516 }
517 return sizeof(ImmutableOopMap) + oms.stream_position();
518 }
519 #endif
520
521 ImmutableOopMapBuilder::ImmutableOopMapBuilder(const OopMapSet* set) : _set(set), _empty(NULL), _last(NULL), _empty_offset(-1), _last_offset(-1), _offset(0), _required(-1), _new_set(NULL) {
522 _mapping = NEW_RESOURCE_ARRAY(Mapping, _set->size());
523 }
524
525 int ImmutableOopMapBuilder::size_for(const OopMap* map) const {
526 return align_up((int)sizeof(ImmutableOopMap) + map->data_size(), 8);
527 }
528
529 int ImmutableOopMapBuilder::heap_size() {
530 int base = sizeof(ImmutableOopMapSet);
531 base = align_up(base, 8);
532
533 // all of ours pc / offset pairs
534 int pairs = _set->size() * sizeof(ImmutableOopMapPair);
535 pairs = align_up(pairs, 8);
536
537 for (int i = 0; i < _set->size(); ++i) {
538 int size = 0;
539 OopMap* map = _set->at(i);
540
541 if (is_empty(map)) {
542 /* only keep a single empty map in the set */
543 if (has_empty()) {
544 _mapping[i].set(Mapping::OOPMAP_EMPTY, _empty_offset, 0, map, _empty);
545 } else {
546 _empty_offset = _offset;
547 _empty = map;
548 size = size_for(map);
549 _mapping[i].set(Mapping::OOPMAP_NEW, _offset, size, map);
550 }
551 } else if (is_last_duplicate(map)) {
552 /* if this entry is identical to the previous one, just point it there */
553 _mapping[i].set(Mapping::OOPMAP_DUPLICATE, _last_offset, 0, map, _last);
554 } else {
555 /* not empty, not an identical copy of the previous entry */
556 size = size_for(map);
557 _mapping[i].set(Mapping::OOPMAP_NEW, _offset, size, map);
558 _last_offset = _offset;
559 _last = map;
560 }
561
562 assert(_mapping[i]._map == map, "check");
563 _offset += size;
564 }
565
566 int total = base + pairs + _offset;
567 DEBUG_ONLY(total += 8);
568 _required = total;
569 return total;
570 }
571
572 void ImmutableOopMapBuilder::fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set) {
573 assert(offset < set->nr_of_bytes(), "check");
574 new ((address) pair) ImmutableOopMapPair(map->offset(), offset);
575 }
576
577 int ImmutableOopMapBuilder::fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set) {
578 fill_pair(pair, map, offset, set);
579 address addr = (address) pair->get_from(_new_set); // location of the ImmutableOopMap
580
581 new (addr) ImmutableOopMap(map);
582 return size_for(map);
583 }
584
585 void ImmutableOopMapBuilder::fill(ImmutableOopMapSet* set, int sz) {
586 ImmutableOopMapPair* pairs = set->get_pairs();
587
588 for (int i = 0; i < set->count(); ++i) {
589 const OopMap* map = _mapping[i]._map;
590 ImmutableOopMapPair* pair = NULL;
591 int size = 0;
592
593 if (_mapping[i]._kind == Mapping::OOPMAP_NEW) {
594 size = fill_map(&pairs[i], map, _mapping[i]._offset, set);
595 } else if (_mapping[i]._kind == Mapping::OOPMAP_DUPLICATE || _mapping[i]._kind == Mapping::OOPMAP_EMPTY) {
596 fill_pair(&pairs[i], map, _mapping[i]._offset, set);
597 }
598
599 const ImmutableOopMap* nv = set->find_map_at_offset(map->offset());
600 assert(memcmp(map->data(), nv->data_addr(), map->data_size()) == 0, "check identity");
601 }
602 }
603
604 #ifdef ASSERT
605 void ImmutableOopMapBuilder::verify(address buffer, int size, const ImmutableOopMapSet* set) {
606 for (int i = 0; i < 8; ++i) {
607 assert(buffer[size - 8 + i] == (unsigned char) 0xff, "overwritten memory check");
608 }
609
610 for (int i = 0; i < set->count(); ++i) {
611 const ImmutableOopMapPair* pair = set->pair_at(i);
612 assert(pair->oopmap_offset() < set->nr_of_bytes(), "check size");
613 const ImmutableOopMap* map = pair->get_from(set);
614 int nr_of_bytes = map->nr_of_bytes();
615 assert(pair->oopmap_offset() + nr_of_bytes <= set->nr_of_bytes(), "check size + size");
616 }
617 }
618 #endif
619
620 ImmutableOopMapSet* ImmutableOopMapBuilder::generate_into(address buffer) {
621 DEBUG_ONLY(memset(&buffer[_required-8], 0xff, 8));
622
623 _new_set = new (buffer) ImmutableOopMapSet(_set, _required);
624 fill(_new_set, _required);
625
626 DEBUG_ONLY(verify(buffer, _required, _new_set));
627
628 return _new_set;
629 }
630
631 ImmutableOopMapSet* ImmutableOopMapBuilder::build() {
632 _required = heap_size();
633
634 // We need to allocate a chunk big enough to hold the ImmutableOopMapSet and all of its ImmutableOopMaps
635 address buffer = NEW_C_HEAP_ARRAY(unsigned char, _required, mtCode);
636 return generate_into(buffer);
637 }
638
639 ImmutableOopMapSet* ImmutableOopMapSet::build_from(const OopMapSet* oopmap_set) {
640 ResourceMark mark;
641 ImmutableOopMapBuilder builder(oopmap_set);
642 return builder.build();
643 }
644
645
646 //------------------------------DerivedPointerTable---------------------------
647
648 #if COMPILER2_OR_JVMCI
649
650 class DerivedPointerTable::Entry : public CHeapObj<mtCompiler> {
651 oop* _location; // Location of derived pointer, also pointing to base
652 intptr_t _offset; // Offset from base pointer
653 Entry* volatile _next;
654
655 static Entry* volatile* next_ptr(Entry& entry) { return &entry._next; }
656
657 public:
658 Entry(oop* location, intptr_t offset) :
659 _location(location), _offset(offset), _next(NULL) {}
660
661 oop* location() const { return _location; }
662 intptr_t offset() const { return _offset; }
663 Entry* next() const { return _next; }
664
665 typedef LockFreeStack<Entry, &next_ptr> List;
666 static List* _list;
667 };
668
669 DerivedPointerTable::Entry::List* DerivedPointerTable::Entry::_list = NULL;
670 bool DerivedPointerTable::_active = false;
671
672 bool DerivedPointerTable::is_empty() {
673 return Entry::_list == NULL || Entry::_list->empty();
674 }
675
676 void DerivedPointerTable::clear() {
677 // The first time, we create the list. Otherwise it should be
678 // empty. If not, then we have probably forgotton to call
679 // update_pointers after last GC/Scavenge.
680 assert (!_active, "should not be active");
681 assert(is_empty(), "table not empty");
682 if (Entry::_list == NULL) {
683 void* mem = NEW_C_HEAP_OBJ(Entry::List, mtCompiler);
684 Entry::_list = ::new (mem) Entry::List();
685 }
686 _active = true;
687 }
688
689 // Returns value of location as an int
690 inline intptr_t value_of_loc(oop *pointer) {
691 return cast_from_oop<intptr_t>((*pointer));
692 }
693
694 void DerivedPointerTable::add(oop *derived_loc, oop *base_loc) {
695 assert(Universe::heap()->is_in_or_null(*base_loc), "not an oop");
696 assert(derived_loc != base_loc, "Base and derived in same location");
697 if (_active) {
698 assert(*derived_loc != (void*)base_loc, "location already added");
699 assert(Entry::_list != NULL, "list must exist");
700 intptr_t offset = value_of_loc(derived_loc) - value_of_loc(base_loc);
701 // This assert is invalid because derived pointers can be
702 // arbitrarily far away from their base.
703 // assert(offset >= -1000000, "wrong derived pointer info");
704
705 if (TraceDerivedPointers) {
706 tty->print_cr(
707 "Add derived pointer@" INTPTR_FORMAT
708 " - Derived: " INTPTR_FORMAT
709 " Base: " INTPTR_FORMAT " (@" INTPTR_FORMAT ") (Offset: " INTX_FORMAT ")",
710 p2i(derived_loc), p2i(*derived_loc), p2i(*base_loc), p2i(base_loc), offset
711 );
712 }
713 // Set derived oop location to point to base.
714 *derived_loc = (oop)base_loc;
715 Entry* entry = new Entry(derived_loc, offset);
716 Entry::_list->push(*entry);
717 }
718 }
719
720 void DerivedPointerTable::update_pointers() {
721 assert(Entry::_list != NULL, "list must exist");
722 Entry* entries = Entry::_list->pop_all();
723 while (entries != NULL) {
724 Entry* entry = entries;
725 entries = entry->next();
726 oop* derived_loc = entry->location();
727 intptr_t offset = entry->offset();
728 // The derived oop was setup to point to location of base
729 oop base = **(oop**)derived_loc;
730 assert(Universe::heap()->is_in_or_null(base), "must be an oop");
731
732 *derived_loc = (oop)(cast_from_oop<address>(base) + offset);
733 assert(value_of_loc(derived_loc) - value_of_loc(&base) == offset, "sanity check");
734
735 if (TraceDerivedPointers) {
736 tty->print_cr("Updating derived pointer@" INTPTR_FORMAT
737 " - Derived: " INTPTR_FORMAT " Base: " INTPTR_FORMAT " (Offset: " INTX_FORMAT ")",
738 p2i(derived_loc), p2i(*derived_loc), p2i(base), offset);
739 }
740
741 // Delete entry
742 delete entry;
743 }
744 assert(Entry::_list->empty(), "invariant");
745 _active = false;
746 }
747
748 #endif // COMPILER2_OR_JVMCI