1 /*
2 * Copyright (c) 1997, 2025, 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 "asm/codeBuffer.hpp"
26 #include "asm/macroAssembler.inline.hpp"
27 #include "memory/resourceArea.hpp"
28 #include "oops/access.inline.hpp"
29 #include "oops/klass.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "prims/vectorSupport.hpp"
32 #include "runtime/continuation.hpp"
33 #include "runtime/interfaceSupport.inline.hpp"
34 #include "runtime/timerTrace.hpp"
35 #include "runtime/sharedRuntime.hpp"
36 #include "runtime/stubRoutines.hpp"
37 #include "utilities/align.hpp"
38 #include "utilities/copy.hpp"
39 #ifdef COMPILER2
40 #include "opto/runtime.hpp"
41 #endif
42
43 UnsafeMemoryAccess* UnsafeMemoryAccess::_table = nullptr;
44 int UnsafeMemoryAccess::_table_length = 0;
45 int UnsafeMemoryAccess::_table_max_length = 0;
46 address UnsafeMemoryAccess::_common_exit_stub_pc = nullptr;
47
48 // Implementation of StubRoutines - for a description of how to
49 // declare new blobs, stubs and entries , see stubDefinitions.hpp.
50
51 // define arrays to hold stub and blob names
52
53 // use a template to generate the initializer for the blob names array
54
55 #define DEFINE_BLOB_NAME(blob_name) \
56 # blob_name,
57
58 const char* StubRoutines::_blob_names[StubGenBlobId::NUM_BLOBIDS] = {
59 STUBGEN_BLOBS_DO(DEFINE_BLOB_NAME)
60 };
61
62 #undef DEFINE_BLOB_NAME
63
64 #define DEFINE_STUB_NAME(blob_name, stub_name) \
65 # stub_name , \
66
67 // use a template to generate the initializer for the stub names array
68 const char* StubRoutines::_stub_names[StubGenStubId::NUM_STUBIDS] = {
69 STUBGEN_STUBS_DO(DEFINE_STUB_NAME)
70 };
71
72 #undef DEFINE_STUB_NAME
73
74 // Define fields used to store blobs
75
76 #define DEFINE_BLOB_FIELD(blob_name) \
77 BufferBlob* StubRoutines:: STUBGEN_BLOB_FIELD_NAME(blob_name) = nullptr;
78
79 STUBGEN_BLOBS_DO(DEFINE_BLOB_FIELD)
80
81 #undef DEFINE_BLOB_FIELD
82
83 // Define fields used to store stub entries
84
85 #define DEFINE_ENTRY_FIELD(blob_name, stub_name, field_name, getter_name) \
86 address StubRoutines:: STUB_FIELD_NAME(field_name) = nullptr;
87
88 #define DEFINE_ENTRY_FIELD_INIT(blob_name, stub_name, field_name, getter_name, init_function) \
89 address StubRoutines:: STUB_FIELD_NAME(field_name) = CAST_FROM_FN_PTR(address, init_function);
90
91 #define DEFINE_ENTRY_FIELD_ARRAY(blob_name, stub_name, field_name, getter_name, count) \
92 address StubRoutines:: STUB_FIELD_NAME(field_name)[count] = { nullptr };
93
94 STUBGEN_ENTRIES_DO(DEFINE_ENTRY_FIELD, DEFINE_ENTRY_FIELD_INIT, DEFINE_ENTRY_FIELD_ARRAY)
95
96 #undef DEFINE_ENTRY_FIELD_ARRAY
97 #undef DEFINE_ENTRY_FIELD_INIT
98 #undef DEFINE_ENTRY_FIELD
99
100 jint StubRoutines::_verify_oop_count = 0;
101
102
103 address StubRoutines::_string_indexof_array[4] = { nullptr };
104 address StubRoutines::_vector_f_math[VectorSupport::NUM_VEC_SIZES][VectorSupport::NUM_VECTOR_OP_MATH] = {{nullptr}, {nullptr}};
105 address StubRoutines::_vector_d_math[VectorSupport::NUM_VEC_SIZES][VectorSupport::NUM_VECTOR_OP_MATH] = {{nullptr}, {nullptr}};
106
107 const char* StubRoutines::get_blob_name(StubGenBlobId id) {
108 assert(0 <= id && id < StubGenBlobId::NUM_BLOBIDS, "invalid blob id");
109 return _blob_names[id];
110 }
111
112 const char* StubRoutines::get_stub_name(StubGenStubId id) {
113 assert(0 <= id && id < StubGenStubId::NUM_STUBIDS, "invalid stub id");
114 return _stub_names[id];
115 }
116
117 #ifdef ASSERT
118
119 // array holding start and end indices for stub ids associated with a
120 // given blob. Given a blob with id (StubGenBlobId) blob_id for any
121 // stub with id (StubGenStubId) stub_id declared within the blob:
122 // _blob_offsets[blob_id] <= stub_id < _blob_offsets[blob_id+1]
123
124 static int _blob_limits[StubGenBlobId::NUM_BLOBIDS + 1];
125
126 // macro used to compute blob limits
127 #define BLOB_COUNT(blob_name) \
128 counter += StubGenStubId_ ## blob_name :: NUM_STUBIDS_ ## blob_name; \
129 _blob_limits[++index] = counter; \
130
131 // macro that checks stubs are associated with the correct blobs
132 #define STUB_VERIFY(blob_name, stub_name) \
133 localStubId = (int) (StubGenStubId_ ## blob_name :: blob_name ## _ ## stub_name ## _id); \
134 globalStubId = (int) (StubGenStubId:: stub_name ## _id); \
135 blobId = (int) (StubGenBlobId:: blob_name ## _id); \
136 assert((globalStubId >= _blob_limits[blobId] && \
137 globalStubId < _blob_limits[blobId+1]), \
138 "stub " # stub_name " uses incorrect blob name " # blob_name); \
139 assert(globalStubId == _blob_limits[blobId] + localStubId, \
140 "stub " # stub_name " id found at wrong offset!"); \
141
142 bool verifyStubIds() {
143 // first compute the blob limits
144 int counter = 0;
145 int index = 0;
146 // populate offsets table with cumulative total of local enum counts
147 STUBGEN_BLOBS_DO(BLOB_COUNT);
148
149 // ensure 1) global stub ids lie in the range of the associated blob
150 // and 2) each blob's base + local stub id == global stub id
151 int globalStubId, blobId, localStubId;
152 STUBGEN_STUBS_DO(STUB_VERIFY);
153 return true;
154 }
155
156 #undef BLOB_COUNT
157 #undef STUB_VERIFY
158
159 // ensure we verify the blob ids when this compile unit is first entered
160 bool _verified_stub_ids = verifyStubIds();
161
162
163 // macro used by stub to blob translation
164
165 #define BLOB_CHECK_OFFSET(blob_name) \
166 if (id < _blob_limits[((int)blobId) + 1]) { return blobId; } \
167 blobId = StubGenBlobId:: blob_name ## _id; \
168
169 // translate a global stub id to an associated blob id based on the
170 // computed blob limits
171
172 StubGenBlobId StubRoutines::stub_to_blob(StubGenStubId stubId) {
173 int id = (int)stubId;
174 assert(id > ((int)StubGenStubId::NO_STUBID) && id < ((int)StubGenStubId::NUM_STUBIDS), "stub id out of range!");
175 // start with no blob to catch stub id == -1
176 StubGenBlobId blobId = StubGenBlobId::NO_BLOBID;
177 STUBGEN_BLOBS_DO(BLOB_CHECK_OFFSET);
178 // if we reach here we should have the last blob id
179 assert(blobId == StubGenBlobId::NUM_BLOBIDS - 1, "unexpected blob id");
180 return blobId;
181 }
182
183 #endif // ASSERT
184
185 // Initialization
186 //
187 // Note: to break cycle with universe initialization, stubs are generated in two phases.
188 // The first one generates stubs needed during universe init (e.g., _handle_must_compile_first_entry).
189 // The second phase includes all other stubs (which may depend on universe being initialized.)
190
191 extern void StubGenerator_generate(CodeBuffer* code, StubGenBlobId blob_id); // only interface to generators
192
193 void UnsafeMemoryAccess::create_table(int max_size) {
194 UnsafeMemoryAccess::_table = new UnsafeMemoryAccess[max_size];
195 UnsafeMemoryAccess::_table_max_length = max_size;
196 }
197
198 bool UnsafeMemoryAccess::contains_pc(address pc) {
199 for (int i = 0; i < UnsafeMemoryAccess::_table_length; i++) {
200 UnsafeMemoryAccess* entry = &UnsafeMemoryAccess::_table[i];
201 if (pc >= entry->start_pc() && pc < entry->end_pc()) {
202 return true;
203 }
204 }
205 return false;
206 }
207
208 address UnsafeMemoryAccess::page_error_continue_pc(address pc) {
209 for (int i = 0; i < UnsafeMemoryAccess::_table_length; i++) {
210 UnsafeMemoryAccess* entry = &UnsafeMemoryAccess::_table[i];
211 if (pc >= entry->start_pc() && pc < entry->end_pc()) {
212 return entry->error_exit_pc();
213 }
214 }
215 return nullptr;
216 }
217
218
219 static BufferBlob* initialize_stubs(StubGenBlobId blob_id,
220 int code_size, int max_aligned_stubs,
221 const char* timer_msg,
222 const char* buffer_name,
223 const char* assert_msg) {
224 ResourceMark rm;
225 TraceTime timer(timer_msg, TRACETIME_LOG(Info, startuptime));
226 // Add extra space for large CodeEntryAlignment
227 int size = code_size + CodeEntryAlignment * max_aligned_stubs;
228 BufferBlob* stubs_code = BufferBlob::create(buffer_name, size);
229 if (stubs_code == nullptr) {
230 vm_exit_out_of_memory(code_size, OOM_MALLOC_ERROR, "CodeCache: no room for %s", buffer_name);
231 }
232 CodeBuffer buffer(stubs_code);
233 StubGenerator_generate(&buffer, blob_id);
234 // When new stubs added we need to make sure there is some space left
235 // to catch situation when we should increase size again.
236 assert(code_size == 0 || buffer.insts_remaining() > 200, "increase %s", assert_msg);
237
238 LogTarget(Info, stubs) lt;
239 if (lt.is_enabled()) {
240 LogStream ls(lt);
241 ls.print_cr("%s\t [" INTPTR_FORMAT ", " INTPTR_FORMAT "] used: %d, free: %d",
242 buffer_name, p2i(stubs_code->content_begin()), p2i(stubs_code->content_end()),
243 buffer.total_content_size(), buffer.insts_remaining());
244 }
245 return stubs_code;
246 }
247
248 #define DEFINE_BLOB_INIT_METHOD(blob_name) \
249 void StubRoutines::initialize_ ## blob_name ## _stubs() { \
250 if (STUBGEN_BLOB_FIELD_NAME(blob_name) == nullptr) { \
251 StubGenBlobId blob_id = StubGenBlobId:: STUB_ID_NAME(blob_name); \
252 int size = _ ## blob_name ## _code_size; \
253 int max_aligned_size = 10; \
254 const char* timer_msg = "StubRoutines generation " # blob_name " stubs"; \
255 const char* name = "StubRoutines (" # blob_name "stubs)"; \
256 const char* assert_msg = "_" # blob_name "_code_size"; \
257 STUBGEN_BLOB_FIELD_NAME(blob_name) = \
258 initialize_stubs(blob_id, size, max_aligned_size, timer_msg, \
259 name, assert_msg); \
260 } \
261 }
262
263
264 STUBGEN_BLOBS_DO(DEFINE_BLOB_INIT_METHOD)
265
266 #undef DEFINE_BLOB_INIT_METHOD
267
268
269 #define DEFINE_BLOB_INIT_FUNCTION(blob_name) \
270 void blob_name ## _stubs_init() { \
271 StubRoutines::initialize_ ## blob_name ## _stubs(); \
272 }
273
274 STUBGEN_BLOBS_DO(DEFINE_BLOB_INIT_FUNCTION)
275
276 #undef DEFINE_BLOB_INIT_FUNCTION
277
278 /*
279 * we generate the underlying driver method but this wrapper is needed
280 * to perform special handling depending on where the compiler init
281 * gets called from. it ought to be possible to remove this at some
282 * point and have adeterminate ordered init.
283 */
284
285 void compiler_stubs_init(bool in_compiler_thread) {
286 if (in_compiler_thread && DelayCompilerStubsGeneration) {
287 // Temporarily revert state of stubs generation because
288 // it is called after final_stubs_init() finished
289 // during compiler runtime initialization.
290 // It is fine because these stubs are only used by
291 // compiled code and compiler is not running yet.
292 StubCodeDesc::unfreeze();
293 StubRoutines::initialize_compiler_stubs();
294 StubCodeDesc::freeze();
295 } else if (!in_compiler_thread && !DelayCompilerStubsGeneration) {
296 StubRoutines::initialize_compiler_stubs();
297 }
298 }
299
300
301 //
302 // Default versions of arraycopy functions
303 //
304
305 JRT_LEAF(void, StubRoutines::jbyte_copy(jbyte* src, jbyte* dest, size_t count))
306 #ifndef PRODUCT
307 SharedRuntime::_jbyte_array_copy_ctr++; // Slow-path byte array copy
308 #endif // !PRODUCT
309 Copy::conjoint_jbytes_atomic(src, dest, count);
310 JRT_END
311
312 JRT_LEAF(void, StubRoutines::jshort_copy(jshort* src, jshort* dest, size_t count))
313 #ifndef PRODUCT
314 SharedRuntime::_jshort_array_copy_ctr++; // Slow-path short/char array copy
315 #endif // !PRODUCT
316 Copy::conjoint_jshorts_atomic(src, dest, count);
317 JRT_END
318
319 JRT_LEAF(void, StubRoutines::jint_copy(jint* src, jint* dest, size_t count))
320 #ifndef PRODUCT
321 SharedRuntime::_jint_array_copy_ctr++; // Slow-path int/float array copy
322 #endif // !PRODUCT
323 Copy::conjoint_jints_atomic(src, dest, count);
324 JRT_END
325
326 JRT_LEAF(void, StubRoutines::jlong_copy(jlong* src, jlong* dest, size_t count))
327 #ifndef PRODUCT
328 SharedRuntime::_jlong_array_copy_ctr++; // Slow-path long/double array copy
329 #endif // !PRODUCT
330 Copy::conjoint_jlongs_atomic(src, dest, count);
331 JRT_END
332
333 JRT_LEAF(void, StubRoutines::oop_copy(oop* src, oop* dest, size_t count))
334 #ifndef PRODUCT
335 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
336 #endif // !PRODUCT
337 assert(count != 0, "count should be non-zero");
338 ArrayAccess<>::oop_arraycopy_raw((HeapWord*)src, (HeapWord*)dest, count);
339 JRT_END
340
341 JRT_LEAF(void, StubRoutines::oop_copy_uninit(oop* src, oop* dest, size_t count))
342 #ifndef PRODUCT
343 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
344 #endif // !PRODUCT
345 assert(count != 0, "count should be non-zero");
346 ArrayAccess<IS_DEST_UNINITIALIZED>::oop_arraycopy_raw((HeapWord*)src, (HeapWord*)dest, count);
347 JRT_END
348
349 JRT_LEAF(void, StubRoutines::arrayof_jbyte_copy(HeapWord* src, HeapWord* dest, size_t count))
350 #ifndef PRODUCT
351 SharedRuntime::_jbyte_array_copy_ctr++; // Slow-path byte array copy
352 #endif // !PRODUCT
353 Copy::arrayof_conjoint_jbytes(src, dest, count);
354 JRT_END
355
356 JRT_LEAF(void, StubRoutines::arrayof_jshort_copy(HeapWord* src, HeapWord* dest, size_t count))
357 #ifndef PRODUCT
358 SharedRuntime::_jshort_array_copy_ctr++; // Slow-path short/char array copy
359 #endif // !PRODUCT
360 Copy::arrayof_conjoint_jshorts(src, dest, count);
361 JRT_END
362
363 JRT_LEAF(void, StubRoutines::arrayof_jint_copy(HeapWord* src, HeapWord* dest, size_t count))
364 #ifndef PRODUCT
365 SharedRuntime::_jint_array_copy_ctr++; // Slow-path int/float array copy
366 #endif // !PRODUCT
367 Copy::arrayof_conjoint_jints(src, dest, count);
368 JRT_END
369
370 JRT_LEAF(void, StubRoutines::arrayof_jlong_copy(HeapWord* src, HeapWord* dest, size_t count))
371 #ifndef PRODUCT
372 SharedRuntime::_jlong_array_copy_ctr++; // Slow-path int/float array copy
373 #endif // !PRODUCT
374 Copy::arrayof_conjoint_jlongs(src, dest, count);
375 JRT_END
376
377 JRT_LEAF(void, StubRoutines::arrayof_oop_copy(HeapWord* src, HeapWord* dest, size_t count))
378 #ifndef PRODUCT
379 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
380 #endif // !PRODUCT
381 assert(count != 0, "count should be non-zero");
382 ArrayAccess<ARRAYCOPY_ARRAYOF>::oop_arraycopy_raw(src, dest, count);
383 JRT_END
384
385 JRT_LEAF(void, StubRoutines::arrayof_oop_copy_uninit(HeapWord* src, HeapWord* dest, size_t count))
386 #ifndef PRODUCT
387 SharedRuntime::_oop_array_copy_ctr++; // Slow-path oop array copy
388 #endif // !PRODUCT
389 assert(count != 0, "count should be non-zero");
390 ArrayAccess<ARRAYCOPY_ARRAYOF | IS_DEST_UNINITIALIZED>::oop_arraycopy_raw(src, dest, count);
391 JRT_END
392
393 address StubRoutines::select_fill_function(BasicType t, bool aligned, const char* &name) {
394 #define RETURN_STUB(xxx_fill) { \
395 name = #xxx_fill; \
396 return StubRoutines::xxx_fill(); }
397
398 switch (t) {
399 case T_BYTE:
400 case T_BOOLEAN:
401 if (!aligned) RETURN_STUB(jbyte_fill);
402 RETURN_STUB(arrayof_jbyte_fill);
403 case T_CHAR:
404 case T_SHORT:
405 if (!aligned) RETURN_STUB(jshort_fill);
406 RETURN_STUB(arrayof_jshort_fill);
407 case T_INT:
408 case T_FLOAT:
409 if (!aligned) RETURN_STUB(jint_fill);
410 RETURN_STUB(arrayof_jint_fill);
411 case T_DOUBLE:
412 case T_LONG:
413 case T_ARRAY:
414 case T_OBJECT:
415 case T_NARROWOOP:
416 case T_NARROWKLASS:
417 case T_ADDRESS:
418 case T_VOID:
419 // Currently unsupported
420 return nullptr;
421
422 default:
423 ShouldNotReachHere();
424 return nullptr;
425 }
426
427 #undef RETURN_STUB
428 }
429
430 // constants for computing the copy function
431 enum {
432 COPYFUNC_UNALIGNED = 0,
433 COPYFUNC_ALIGNED = 1, // src, dest aligned to HeapWordSize
434 COPYFUNC_CONJOINT = 0,
435 COPYFUNC_DISJOINT = 2 // src != dest, or transfer can descend
436 };
437
438 // Note: The condition "disjoint" applies also for overlapping copies
439 // where an descending copy is permitted (i.e., dest_offset <= src_offset).
440 address
441 StubRoutines::select_arraycopy_function(BasicType t, bool aligned, bool disjoint, const char* &name, bool dest_uninitialized) {
442 int selector =
443 (aligned ? COPYFUNC_ALIGNED : COPYFUNC_UNALIGNED) +
444 (disjoint ? COPYFUNC_DISJOINT : COPYFUNC_CONJOINT);
445
446 #define RETURN_STUB(xxx_arraycopy) { \
447 name = #xxx_arraycopy; \
448 return StubRoutines::xxx_arraycopy(); }
449
450 #define RETURN_STUB_PARM(xxx_arraycopy, parm) { \
451 name = parm ? #xxx_arraycopy "_uninit": #xxx_arraycopy; \
452 return StubRoutines::xxx_arraycopy(parm); }
453
454 switch (t) {
455 case T_BYTE:
456 case T_BOOLEAN:
457 switch (selector) {
458 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jbyte_arraycopy);
459 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jbyte_arraycopy);
460 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jbyte_disjoint_arraycopy);
461 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jbyte_disjoint_arraycopy);
462 }
463 case T_CHAR:
464 case T_SHORT:
465 switch (selector) {
466 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jshort_arraycopy);
467 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jshort_arraycopy);
468 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jshort_disjoint_arraycopy);
469 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jshort_disjoint_arraycopy);
470 }
471 case T_INT:
472 case T_FLOAT:
473 switch (selector) {
474 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jint_arraycopy);
475 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jint_arraycopy);
476 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jint_disjoint_arraycopy);
477 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jint_disjoint_arraycopy);
478 }
479 case T_DOUBLE:
480 case T_LONG:
481 switch (selector) {
482 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jlong_arraycopy);
483 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jlong_arraycopy);
484 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB(jlong_disjoint_arraycopy);
485 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB(arrayof_jlong_disjoint_arraycopy);
486 }
487 case T_ARRAY:
488 case T_OBJECT:
489 switch (selector) {
490 case COPYFUNC_CONJOINT | COPYFUNC_UNALIGNED: RETURN_STUB_PARM(oop_arraycopy, dest_uninitialized);
491 case COPYFUNC_CONJOINT | COPYFUNC_ALIGNED: RETURN_STUB_PARM(arrayof_oop_arraycopy, dest_uninitialized);
492 case COPYFUNC_DISJOINT | COPYFUNC_UNALIGNED: RETURN_STUB_PARM(oop_disjoint_arraycopy, dest_uninitialized);
493 case COPYFUNC_DISJOINT | COPYFUNC_ALIGNED: RETURN_STUB_PARM(arrayof_oop_disjoint_arraycopy, dest_uninitialized);
494 }
495 default:
496 ShouldNotReachHere();
497 return nullptr;
498 }
499
500 #undef RETURN_STUB
501 #undef RETURN_STUB_PARM
502 }
503
504 UnsafeMemoryAccessMark::UnsafeMemoryAccessMark(StubCodeGenerator* cgen, bool add_entry, bool continue_at_scope_end, address error_exit_pc) {
505 _cgen = cgen;
506 _ucm_entry = nullptr;
507 if (add_entry) {
508 address err_exit_pc = nullptr;
509 if (!continue_at_scope_end) {
510 err_exit_pc = error_exit_pc != nullptr ? error_exit_pc : UnsafeMemoryAccess::common_exit_stub_pc();
511 }
512 assert(err_exit_pc != nullptr || continue_at_scope_end, "error exit not set");
513 _ucm_entry = UnsafeMemoryAccess::add_to_table(_cgen->assembler()->pc(), nullptr, err_exit_pc);
514 }
515 }
516
517 UnsafeMemoryAccessMark::~UnsafeMemoryAccessMark() {
518 if (_ucm_entry != nullptr) {
519 _ucm_entry->set_end_pc(_cgen->assembler()->pc());
520 if (_ucm_entry->error_exit_pc() == nullptr) {
521 _ucm_entry->set_error_exit_pc(_cgen->assembler()->pc());
522 }
523 }
524 }