1 /*
2 * Copyright (c) 2017, 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 "gc/shared/barrierSet.hpp"
27 #include "gc/shared/gcLocker.inline.hpp"
28 #include "interpreter/interpreter.hpp"
29 #include "logging/log.hpp"
30 #include "memory/metadataFactory.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "oops/fieldStreams.hpp"
34 #include "oops/method.hpp"
35 #include "oops/objArrayKlass.hpp"
36 #include "oops/valueKlass.hpp"
37 #include "oops/valueArrayKlass.hpp"
38 #include "runtime/signature.hpp"
39 #include "utilities/copy.hpp"
40
41 int ValueKlass::first_field_offset() const {
42 #ifdef ASSERT
43 int first_offset = INT_MAX;
44 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
45 if (fs.offset() < first_offset) first_offset= fs.offset();
46 }
47 #endif
48 int base_offset = instanceOopDesc::base_offset_in_bytes();
49 // The first field of value types is aligned on a long boundary
50 base_offset = align_up(base_offset, BytesPerLong);
51 assert(base_offset == first_offset, "inconsistent offsets");
52 return base_offset;
53 }
54
55 int ValueKlass::raw_value_byte_size() const {
56 int heapOopAlignedSize = nonstatic_field_size() << LogBytesPerHeapOop;
57 // If bigger than 64 bits or needs oop alignment, then use jlong aligned
58 // which for values should be jlong aligned, asserts in raw_field_copy otherwise
59 if (heapOopAlignedSize >= longSize || contains_oops()) {
60 return heapOopAlignedSize;
61 }
62 // Small primitives...
63 // If a few small basic type fields, return the actual size, i.e.
64 // 1 byte = 1
65 // 2 byte = 2
66 // 3 byte = 4, because pow2 needed for element stores
67 int first_offset = first_field_offset();
68 int last_offset = 0; // find the last offset, add basic type size
69 int last_tsz = 0;
70 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
71 if (fs.offset() > last_offset) {
72 BasicType type = fs.field_descriptor().field_type();
73 if (is_java_primitive(type)) {
74 last_tsz = type2aelembytes(type);
75 } else if (type == T_VALUETYPE) {
76 // Not just primitives. Layout aligns embedded value, so use jlong aligned it is
77 return heapOopAlignedSize;
78 } else {
79 guarantee(0, "Unknown type %d", type);
80 }
81 assert(last_tsz != 0, "Invariant");
82 last_offset = fs.offset();
83 }
84 }
85 // Assumes VT with no fields are meaningless and illegal
86 last_offset += last_tsz;
87 assert(last_offset > first_offset && last_tsz, "Invariant");
88 return 1 << upper_log2(last_offset - first_offset);
89 }
90
91 instanceOop ValueKlass::allocate_instance(TRAPS) {
92 int size = size_helper(); // Query before forming handle.
93
94 return (instanceOop)CollectedHeap::obj_allocate(this, size, CHECK_NULL);
95 }
96
97 instanceOop ValueKlass::allocate_buffered_or_heap_instance(bool* in_heap, TRAPS) {
98 assert(THREAD->is_Java_thread(), "Only Java threads can call this method");
99
100 instanceOop value = NULL;
101 if (is_bufferable()) {
102 value = (instanceOop)VTBuffer::allocate_value(this, CHECK_NULL);
103 *in_heap = false;
104 }
105 if (value == NULL) {
106 log_info(valuetypes)("Value buffering failed, allocating in the Java heap");
107 value = allocate_instance(CHECK_NULL);
108 *in_heap = true;
109 }
110 return value;
111 }
112
113 bool ValueKlass::is_atomic() {
114 return (nonstatic_field_size() * heapOopSize) <= longSize;
115 }
116
117 int ValueKlass::nonstatic_oop_count() {
118 int oops = 0;
119 int map_count = nonstatic_oop_map_count();
120 OopMapBlock* block = start_of_nonstatic_oop_maps();
121 OopMapBlock* end = block + map_count;
122 while (block != end) {
123 oops += block->count();
124 block++;
125 }
126 return oops;
127 }
128
129 // Arrays of...
130
131 bool ValueKlass::flatten_array() {
132 if (!ValueArrayFlatten) {
133 return false;
134 }
135
136 int elem_bytes = raw_value_byte_size();
137 // Too big
138 if ((ValueArrayElemMaxFlatSize >= 0) && (elem_bytes > ValueArrayElemMaxFlatSize)) {
139 return false;
140 }
141 // Too many embedded oops
142 if ((ValueArrayElemMaxFlatOops >= 0) && (nonstatic_oop_count() > ValueArrayElemMaxFlatOops)) {
143 return false;
144 }
145
146 return true;
147 }
148
149
150 Klass* ValueKlass::array_klass_impl(bool or_null, int n, TRAPS) {
151 if (!flatten_array()) {
152 return InstanceKlass::array_klass_impl(or_null, n, THREAD);
153 }
154
155 // Basically the same as instanceKlass, but using "ValueArrayKlass::allocate_klass"
156 if (array_klasses() == NULL) {
157 if (or_null) return NULL;
158
159 ResourceMark rm;
160 JavaThread *jt = (JavaThread *)THREAD;
161 {
162 // Atomic creation of array_klasses
163 MutexLocker mc(Compile_lock, THREAD); // for vtables
164 MutexLocker ma(MultiArray_lock, THREAD);
165
166 // Check if update has already taken place
167 if (array_klasses() == NULL) {
168 Klass* ak;
169 if (is_atomic() || (!ValueArrayAtomicAccess)) {
170 ak = ValueArrayKlass::allocate_klass(this, CHECK_NULL);
171 } else {
172 ak = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), 1, this, CHECK_NULL);
173 }
174 set_array_klasses(ak);
175 }
176 }
177 }
178 // _this will always be set at this point
179 ArrayKlass* ak = ArrayKlass::cast(array_klasses());
180 if (or_null) {
181 return ak->array_klass_or_null(n);
182 }
183 return ak->array_klass(n, THREAD);
184 }
185
186 Klass* ValueKlass::array_klass_impl(bool or_null, TRAPS) {
187 return array_klass_impl(or_null, 1, THREAD);
188 }
189
190 void ValueKlass::raw_field_copy(void* src, void* dst, size_t raw_byte_size) {
191 /*
192 * Try not to shear fields even if not an atomic store...
193 *
194 * First 3 cases handle value array store, otherwise works on the same basis
195 * as JVM_Clone, at this size data is aligned. The order of primitive types
196 * is largest to smallest, and it not possible for fields to stradle long
197 * copy boundaries.
198 *
199 * If MT without exclusive access, possible to observe partial value store,
200 * but not partial primitive and reference field values
201 */
202 switch (raw_byte_size) {
203 case 1:
204 *((jbyte*) dst) = *(jbyte*)src;
205 break;
206 case 2:
207 *((jshort*) dst) = *(jshort*)src;
208 break;
209 case 4:
210 *((jint*) dst) = *(jint*) src;
211 break;
212 default:
213 assert(raw_byte_size % sizeof(jlong) == 0, "Unaligned raw_byte_size");
214 Copy::conjoint_jlongs_atomic((jlong*)src, (jlong*)dst, raw_byte_size >> LogBytesPerLong);
215 }
216 }
217
218 /*
219 * Store the value of this klass contained with src into dst.
220 *
221 * This operation is appropriate for use from vastore, vaload and putfield (for values)
222 *
223 * GC barriers currently can lock with no safepoint check and allocate c-heap,
224 * so raw point is "safe" for now.
225 *
226 * Going forward, look to use machine generated (stub gen or bc) version for most used klass layouts
227 *
228 */
229 void ValueKlass::value_store(void* src, void* dst, size_t raw_byte_size, bool dst_heap, bool dst_uninitialized) {
230 if (contains_oops()) {
231 if (dst_heap) {
232 // src/dst aren't oops, need offset to adjust oop map offset
233 const address dst_oop_addr = ((address) dst) - first_field_offset();
234
235 // Pre-barriers...
236 OopMapBlock* map = start_of_nonstatic_oop_maps();
237 OopMapBlock* const end = map + nonstatic_oop_map_count();
238 while (map != end) {
239 // Shame we can't just use the existing oop iterator...src/dst aren't oop
240 address doop_address = dst_oop_addr + map->offset();
241 // TEMP HACK: barrier code need to migrate to => access API (need own versions of value type ops)
242 if (UseCompressedOops) {
243 BarrierSet::barrier_set()->write_ref_array_pre((narrowOop*) doop_address, map->count(), dst_uninitialized);
244 } else {
245 BarrierSet::barrier_set()->write_ref_array_pre((oop*) doop_address, map->count(), dst_uninitialized);
246 }
247 map++;
248 }
249
250 raw_field_copy(src, dst, raw_byte_size);
251
252 // Post-barriers...
253 map = start_of_nonstatic_oop_maps();
254 while (map != end) {
255 address doop_address = dst_oop_addr + map->offset();
256 BarrierSet::barrier_set()->write_ref_array((HeapWord*) doop_address, map->count());
257 map++;
258 }
259 } else { // Buffered value case
260 raw_field_copy(src, dst, raw_byte_size);
261 }
262 } else { // Primitive-only case...
263 raw_field_copy(src, dst, raw_byte_size);
264 }
265 }
266
267 // Value type arguments are not passed by reference, instead each
268 // field of the value type is passed as an argument. This helper
269 // function collects the fields of the value types (including embedded
270 // value type's fields) in a list. Included with the field's type is
271 // the offset of each field in the value type: i2c and c2i adapters
272 // need that to load or store fields. Finally, the list of fields is
273 // sorted in order of increasing offsets: the adapters and the
274 // compiled code need and agreed upon order of fields.
275 //
276 // The list of basic types that is returned starts with a T_VALUETYPE
277 // and ends with an extra T_VOID. T_VALUETYPE/T_VOID are used as
278 // delimiters. Every entry between the two is a field of the value
279 // type. If there's an embedded value type in the list, it also starts
280 // with a T_VALUETYPE and ends with a T_VOID. This is so we can
281 // generate a unique fingerprint for the method's adapters and we can
282 // generate the list of basic types from the interpreter point of view
283 // (value types passed as reference: iterate on the list until a
284 // T_VALUETYPE, drop everything until and including the closing
285 // T_VOID) or the compiler point of view (each field of the value
286 // types is an argument: drop all T_VALUETYPE/T_VOID from the list).
287 GrowableArray<SigEntry> ValueKlass::collect_fields(int base_off) const {
288 GrowableArray<SigEntry> sig_extended;
289 sig_extended.push(SigEntry(T_VALUETYPE, base_off));
290 for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
291 if (fs.access_flags().is_static()) continue;
292 fieldDescriptor& fd = fs.field_descriptor();
293 BasicType bt = fd.field_type();
294 int offset = base_off + fd.offset() - (base_off > 0 ? first_field_offset() : 0);
295 if (bt == T_VALUETYPE) {
296 if (fd.is_flatten()) {
297 Symbol* signature = fd.signature();
298 JavaThread* THREAD = JavaThread::current();
299 oop loader = class_loader();
300 oop domain = protection_domain();
301 ResetNoHandleMark rnhm;
302 HandleMark hm;
303 NoSafepointVerifier nsv;
304 Klass* klass = SystemDictionary::resolve_or_null(signature,
305 Handle(THREAD, loader), Handle(THREAD, domain),
306 THREAD);
307 assert(klass != NULL && !HAS_PENDING_EXCEPTION, "lookup shouldn't fail");
308 const GrowableArray<SigEntry>& embedded = ValueKlass::cast(klass)->collect_fields(offset);
309 sig_extended.appendAll(&embedded);
310 } else {
311 sig_extended.push(SigEntry(T_VALUETYPEPTR, offset));
312 }
313 } else {
314 sig_extended.push(SigEntry(bt, offset));
315 if (bt == T_LONG || bt == T_DOUBLE) {
316 sig_extended.push(SigEntry(T_VOID, offset));
317 }
318 }
319 }
320 int offset = base_off + size_helper()*HeapWordSize - (base_off > 0 ? first_field_offset() : 0);
321 sig_extended.push(SigEntry(T_VOID, offset)); // hack: use T_VOID to mark end of value type fields
322 if (base_off == 0) {
323 sig_extended.sort(SigEntry::compare);
324 }
325 assert(sig_extended.at(0)._bt == T_VALUETYPE && sig_extended.at(sig_extended.length()-1)._bt == T_VOID, "broken structure");
326 return sig_extended;
327 }
328
329 void ValueKlass::initialize_calling_convention() {
330 // Because the pack and unpack handler addresses need to be loadable from generated code,
331 // they are stored at a fixed offset in the klass metadata. Since value type klasses do
332 // not have a vtable, the vtable offset is used to store these addresses.
333 //guarantee(vtable_length() == 0, "vtables are not supported in value klasses");
334 if (ValueTypeReturnedAsFields || ValueTypePassFieldsAsArgs) {
335 Thread* THREAD = Thread::current();
336 assert(!HAS_PENDING_EXCEPTION, "should have no exception");
337 ResourceMark rm;
338 const GrowableArray<SigEntry>& sig_vk = collect_fields();
339 int nb_fields = SigEntry::count_fields(sig_vk)+1;
340 Array<SigEntry>* extended_sig = MetadataFactory::new_array<SigEntry>(class_loader_data(), sig_vk.length(), CHECK_AND_CLEAR);
341 *((Array<SigEntry>**)adr_extended_sig()) = extended_sig;
342 for (int i = 0; i < sig_vk.length(); i++) {
343 extended_sig->at_put(i, sig_vk.at(i));
344 }
345
346 if (ValueTypeReturnedAsFields) {
347 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, nb_fields);
348 sig_bt[0] = T_METADATA;
349 SigEntry::fill_sig_bt(sig_vk, sig_bt+1, nb_fields-1, true);
350 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, nb_fields);
351 int total = SharedRuntime::java_return_convention(sig_bt, regs, nb_fields);
352
353 if (total > 0) {
354 Array<VMRegPair>* return_regs = MetadataFactory::new_array<VMRegPair>(class_loader_data(), nb_fields, CHECK_AND_CLEAR);
355 *((Array<VMRegPair>**)adr_return_regs()) = return_regs;
356 for (int i = 0; i < nb_fields; i++) {
357 return_regs->at_put(i, regs[i]);
358 }
359
360 BufferedValueTypeBlob* buffered_blob = SharedRuntime::generate_buffered_value_type_adapter(this);
361 *((address*)adr_pack_handler()) = buffered_blob->pack_fields();
362 *((address*)adr_unpack_handler()) = buffered_blob->unpack_fields();
363 assert(CodeCache::find_blob(pack_handler()) == buffered_blob, "lost track of blob");
364 }
365 }
366 }
367 }
368
369 void ValueKlass::deallocate_contents(ClassLoaderData* loader_data) {
370 if (extended_sig() != NULL) {
371 MetadataFactory::free_array<SigEntry>(loader_data, extended_sig());
372 }
373 if (return_regs() != NULL) {
374 MetadataFactory::free_array<VMRegPair>(loader_data, return_regs());
375 }
376 cleanup_blobs();
377 InstanceKlass::deallocate_contents(loader_data);
378 }
379
380 void ValueKlass::cleanup(ValueKlass* ik) {
381 ik->cleanup_blobs();
382 }
383
384 void ValueKlass::cleanup_blobs() {
385 if (pack_handler() != NULL) {
386 CodeBlob* buffered_blob = CodeCache::find_blob(pack_handler());
387 assert(buffered_blob->is_buffered_value_type_blob(), "bad blob type");
388 BufferBlob::free((BufferBlob*)buffered_blob);
389 *((address*)adr_pack_handler()) = NULL;
390 *((address*)adr_unpack_handler()) = NULL;
391 }
392 }
393
394 // Can this value type be returned as multiple values?
395 bool ValueKlass::can_be_returned_as_fields() const {
396 return return_regs() != NULL;
397 }
398
399 // Create handles for all oop fields returned in registers that are going to be live across a safepoint
400 void ValueKlass::save_oop_fields(const RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
401 Thread* thread = Thread::current();
402 const Array<SigEntry>* sig_vk = extended_sig();
403 const Array<VMRegPair>* regs = return_regs();
404 int j = 1;
405
406 for (int i = 0; i < sig_vk->length(); i++) {
407 BasicType bt = sig_vk->at(i)._bt;
408 if (bt == T_OBJECT || bt == T_VALUETYPEPTR || bt == T_ARRAY) {
409 int off = sig_vk->at(i)._offset;
410 VMRegPair pair = regs->at(j);
411 address loc = reg_map.location(pair.first());
412 oop v = *(oop*)loc;
413 assert(v == NULL || oopDesc::is_oop(v), "not an oop?");
414 assert(Universe::heap()->is_in_or_null(v), "must be heap pointer");
415 handles.push(Handle(thread, v));
416 }
417 if (bt == T_VALUETYPE) {
418 continue;
419 }
420 if (bt == T_VOID &&
421 sig_vk->at(i-1)._bt != T_LONG &&
422 sig_vk->at(i-1)._bt != T_DOUBLE) {
423 continue;
424 }
425 j++;
426 }
427 assert(j == regs->length(), "missed a field?");
428 }
429
430 // Update oop fields in registers from handles after a safepoint
431 void ValueKlass::restore_oop_results(RegisterMap& reg_map, GrowableArray<Handle>& handles) const {
432 assert(ValueTypeReturnedAsFields, "inconsistent");
433 const Array<SigEntry>* sig_vk = extended_sig();
434 const Array<VMRegPair>* regs = return_regs();
435 assert(regs != NULL, "inconsistent");
436
437 int j = 1;
438 for (int i = 0, k = 0; i < sig_vk->length(); i++) {
439 BasicType bt = sig_vk->at(i)._bt;
440 if (bt == T_OBJECT || bt == T_ARRAY) {
441 int off = sig_vk->at(i)._offset;
442 VMRegPair pair = regs->at(j);
443 address loc = reg_map.location(pair.first());
444 *(oop*)loc = handles.at(k++)();
445 }
446 if (bt == T_VALUETYPE) {
447 continue;
448 }
449 if (bt == T_VOID &&
450 sig_vk->at(i-1)._bt != T_LONG &&
451 sig_vk->at(i-1)._bt != T_DOUBLE) {
452 continue;
453 }
454 j++;
455 }
456 assert(j == regs->length(), "missed a field?");
457 }
458
459 // Fields are in registers. Create an instance of the value type and
460 // initialize it with the values of the fields.
461 oop ValueKlass::realloc_result(const RegisterMap& reg_map, const GrowableArray<Handle>& handles, bool buffered, TRAPS) {
462 bool ignored = false;
463 oop new_vt = NULL;
464 if (buffered) {
465 new_vt = allocate_buffered_or_heap_instance(&ignored, CHECK_NULL);
466 } else {
467 new_vt = allocate_instance(CHECK_NULL);
468 }
469
470 const Array<SigEntry>* sig_vk = extended_sig();
471 const Array<VMRegPair>* regs = return_regs();
472
473 int j = 1;
474 int k = 0;
475 for (int i = 0; i < sig_vk->length(); i++) {
476 BasicType bt = sig_vk->at(i)._bt;
477 if (bt == T_VALUETYPE) {
478 continue;
479 }
480 if (bt == T_VOID) {
481 if (sig_vk->at(i-1)._bt == T_LONG ||
482 sig_vk->at(i-1)._bt == T_DOUBLE) {
483 j++;
484 }
485 continue;
486 }
487 int off = sig_vk->at(i)._offset;
488 VMRegPair pair = regs->at(j);
489 address loc = reg_map.location(pair.first());
490 switch(bt) {
491 case T_BOOLEAN: {
492 jboolean v = *(intptr_t*)loc;
493 *(jboolean*)((address)new_vt + off) = v;
494 break;
495 }
496 case T_CHAR: {
497 jchar v = *(intptr_t*)loc;
498 *(jchar*)((address)new_vt + off) = v;
499 break;
500 }
501 case T_BYTE: {
502 jbyte v = *(intptr_t*)loc;
503 *(jbyte*)((address)new_vt + off) = v;
504 break;
505 }
506 case T_SHORT: {
507 jshort v = *(intptr_t*)loc;
508 *(jshort*)((address)new_vt + off) = v;
509 break;
510 }
511 case T_INT: {
512 jint v = *(intptr_t*)loc;
513 *(jint*)((address)new_vt + off) = v;
514 break;
515 }
516 case T_LONG: {
517 #ifdef _LP64
518 jlong v = *(intptr_t*)loc;
519 *(jlong*)((address)new_vt + off) = v;
520 #else
521 Unimplemented();
522 #endif
523 break;
524 }
525 case T_OBJECT:
526 case T_VALUETYPEPTR:
527 case T_ARRAY: {
528 Handle handle = handles.at(k++);
529 oop v = handle();
530 if (!UseCompressedOops) {
531 oop* p = (oop*)((address)new_vt + off);
532 oopDesc::store_heap_oop(p, v);
533 } else {
534 narrowOop* p = (narrowOop*)((address)new_vt + off);
535 oopDesc::encode_store_heap_oop(p, v);
536 }
537 break;
538 }
539 case T_FLOAT: {
540 jfloat v = *(jfloat*)loc;
541 *(jfloat*)((address)new_vt + off) = v;
542 break;
543 }
544 case T_DOUBLE: {
545 jdouble v = *(jdouble*)loc;
546 *(jdouble*)((address)new_vt + off) = v;
547 break;
548 }
549 default:
550 ShouldNotReachHere();
551 }
552 *(intptr_t*)loc = 0xDEAD;
553 j++;
554 }
555 assert(j == regs->length(), "missed a field?");
556 assert(k == handles.length(), "missed an oop?");
557 return new_vt;
558 }
559
560 // Check the return register for a ValueKlass oop
561 ValueKlass* ValueKlass::returned_value_klass(const RegisterMap& map) {
562 BasicType bt = T_METADATA;
563 VMRegPair pair;
564 int nb = SharedRuntime::java_return_convention(&bt, &pair, 1);
565 assert(nb == 1, "broken");
566
567 address loc = map.location(pair.first());
568 intptr_t ptr = *(intptr_t*)loc;
569 if (is_set_nth_bit(ptr, 0)) {
570 // Oop is tagged, must be a ValueKlass oop
571 clear_nth_bit(ptr, 0);
572 assert(Metaspace::contains((void*)ptr), "should be klass");
573 ValueKlass* vk = (ValueKlass*)ptr;
574 assert(vk->can_be_returned_as_fields(), "must be able to return as fields");
575 return vk;
576 }
577 #ifdef ASSERT
578 // Oop is not tagged, must be a valid oop
579 if (VerifyOops) {
580 oop((HeapWord*)ptr)->verify();
581 }
582 #endif
583 return NULL;
584 }
585
586 void ValueKlass::iterate_over_inside_oops(OopClosure* f, oop value) {
587 assert(!Universe::heap()->is_in_reserved(value), "This method is used on buffered values");
588
589 oop* addr_mirror = (oop*)(value)->mark_addr();
590 f->do_oop_no_buffering(addr_mirror);
591
592 if (!contains_oops()) return;
593
594 OopMapBlock* map = start_of_nonstatic_oop_maps();
595 OopMapBlock* const end_map = map + nonstatic_oop_map_count();
596
597 if (!UseCompressedOops) {
598 for (; map < end_map; map++) {
599 oop* p = (oop*) (((char*)(oopDesc*)value) + map->offset());
600 oop* const end = p + map->count();
601 for (; p < end; ++p) {
602 assert(oopDesc::is_oop_or_null(*p), "Sanity check");
603 f->do_oop(p);
604 }
605 }
606 } else {
607 for (; map < end_map; map++) {
608 narrowOop* p = (narrowOop*) (((char*)(oopDesc*)value) + map->offset());
609 narrowOop* const end = p + map->count();
610 for (; p < end; ++p) {
611 oop o = oopDesc::decode_heap_oop(*p);
612 assert(Universe::heap()->is_in_reserved_or_null(o), "Sanity check");
613 assert(oopDesc::is_oop_or_null(o), "Sanity check");
614 f->do_oop(p);
615 }
616 }
617 }
618 }