1 /*
  2  * Copyright (c) 1997, 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 #ifndef SHARE_RUNTIME_STUBROUTINES_HPP
 26 #define SHARE_RUNTIME_STUBROUTINES_HPP
 27 
 28 #include "code/codeBlob.hpp"
 29 #include "memory/allocation.hpp"
 30 #include "runtime/frame.hpp"
 31 #include "runtime/mutexLocker.hpp"
 32 #include "runtime/stubCodeGenerator.hpp"
 33 #include "utilities/macros.hpp"
 34 
 35 // StubRoutines provides entry points to assembly routines used by
 36 // compiled code and the run-time system. Platform-specific entry
 37 // points are defined in the platform-specific inner class.
 38 //
 39 // Class scheme:
 40 //
 41 //    platform-independent               platform-dependent
 42 //
 43 //    stubRoutines.hpp  <-- included --  stubRoutines_<arch>.hpp
 44 //           ^                                  ^
 45 //           |                                  |
 46 //       implements                         implements
 47 //           |                                  |
 48 //           |                                  |
 49 //    stubRoutines.cpp                   stubRoutines_<arch>.cpp
 50 //    stubRoutines_<os_family>.cpp       stubGenerator_<arch>.cpp
 51 //    stubRoutines_<os_arch>.cpp
 52 //
 53 // Note 1: The important thing is a clean decoupling between stub
 54 //         entry points (interfacing to the whole vm; i.e., 1-to-n
 55 //         relationship) and stub generators (interfacing only to
 56 //         the entry points implementation; i.e., 1-to-1 relationship).
 57 //         This significantly simplifies changes in the generator
 58 //         structure since the rest of the vm is not affected.
 59 //
 60 // Note 2: stubGenerator_<arch>.cpp contains a minimal portion of
 61 //         machine-independent code; namely the generator calls of
 62 //         the generator functions that are used platform-independently.
 63 //         However, it comes with the advantage of having a 1-file
 64 //         implementation of the generator. It should be fairly easy
 65 //         to change, should it become a problem later.
 66 //
 67 // Scheme for adding a new entry point:
 68 //
 69 // 1. determine if it's a platform-dependent or independent entry point
 70 //    a) if platform independent: make subsequent changes in the independent files
 71 //    b) if platform   dependent: make subsequent changes in the   dependent files
 72 // 2. add a private instance variable holding the entry point address
 73 // 3. add a public accessor function to the instance variable
 74 // 4. implement the corresponding generator function in the platform-dependent
 75 //    stubGenerator_<arch>.cpp file and call the function in generate_all() of that file
 76 
 77 class UnsafeCopyMemory : public CHeapObj<mtCode> {
 78  private:
 79   address _start_pc;
 80   address _end_pc;
 81   address _error_exit_pc;
 82  public:
 83   static address           _common_exit_stub_pc;
 84   static UnsafeCopyMemory* _table;
 85   static int               _table_length;
 86   static int               _table_max_length;
 87   UnsafeCopyMemory() : _start_pc(NULL), _end_pc(NULL), _error_exit_pc(NULL) {}
 88   void    set_start_pc(address pc)      { _start_pc = pc; }
 89   void    set_end_pc(address pc)        { _end_pc = pc; }
 90   void    set_error_exit_pc(address pc) { _error_exit_pc = pc; }
 91   address start_pc()      const { return _start_pc; }
 92   address end_pc()        const { return _end_pc; }
 93   address error_exit_pc() const { return _error_exit_pc; }
 94 
 95   static void    set_common_exit_stub_pc(address pc) { _common_exit_stub_pc = pc; }
 96   static address common_exit_stub_pc()               { return _common_exit_stub_pc; }
 97 
 98   static UnsafeCopyMemory* add_to_table(address start_pc, address end_pc, address error_exit_pc) {
 99     guarantee(_table_length < _table_max_length, "Incorrect UnsafeCopyMemory::_table_max_length");
100     UnsafeCopyMemory* entry = &_table[_table_length];
101     entry->set_start_pc(start_pc);
102     entry->set_end_pc(end_pc);
103     entry->set_error_exit_pc(error_exit_pc);
104 
105     _table_length++;
106     return entry;
107   }
108 
109   static bool    contains_pc(address pc);
110   static address page_error_continue_pc(address pc);
111   static void    create_table(int max_size);
112 };
113 
114 class UnsafeCopyMemoryMark : public StackObj {
115  private:
116   UnsafeCopyMemory*  _ucm_entry;
117   StubCodeGenerator* _cgen;
118  public:
119   UnsafeCopyMemoryMark(StubCodeGenerator* cgen, bool add_entry, bool continue_at_scope_end, address error_exit_pc = NULL);
120   ~UnsafeCopyMemoryMark();
121 };
122 
123 class StubRoutines: AllStatic {
124 
125  public:
126   // Dependencies
127   friend class StubGenerator;
128 
129 #include CPU_HEADER(stubRoutines)
130 
131   static jint    _verify_oop_count;
132   static address _verify_oop_subroutine_entry;
133 
134   static address _call_stub_return_address;                // the return PC, when returning to a call stub
135   static address _call_stub_entry;
136   static address _forward_exception_entry;
137   static address _catch_exception_entry;
138   static address _throw_AbstractMethodError_entry;
139   static address _throw_IncompatibleClassChangeError_entry;
140   static address _throw_NullPointerException_at_call_entry;
141   static address _throw_StackOverflowError_entry;
142   static address _throw_delayed_StackOverflowError_entry;
143 
144   static address _atomic_xchg_entry;
145   static address _atomic_xchg_long_entry;
146   static address _atomic_store_entry;
147   static address _atomic_cmpxchg_entry;
148   static address _atomic_cmpxchg_byte_entry;
149   static address _atomic_cmpxchg_long_entry;
150   static address _atomic_add_entry;
151   static address _atomic_add_long_entry;
152   static address _fence_entry;
153   static address _d2i_wrapper;
154   static address _d2l_wrapper;
155 
156   static jint    _fpu_cntrl_wrd_std;
157   static jint    _fpu_cntrl_wrd_24;
158   static jint    _fpu_cntrl_wrd_trunc;
159   static jint    _mxcsr_std;
160   static jint    _fpu_subnormal_bias1[3];
161   static jint    _fpu_subnormal_bias2[3];
162 
163   static BufferBlob* _code1;                               // code buffer for initial routines
164   static BufferBlob* _code2;                               // code buffer for all other routines
165 
166   // Leaf routines which implement arraycopy and their addresses
167   // arraycopy operands aligned on element type boundary
168   static address _jbyte_arraycopy;
169   static address _jshort_arraycopy;
170   static address _jint_arraycopy;
171   static address _jlong_arraycopy;
172   static address _oop_arraycopy, _oop_arraycopy_uninit;
173   static address _jbyte_disjoint_arraycopy;
174   static address _jshort_disjoint_arraycopy;
175   static address _jint_disjoint_arraycopy;
176   static address _jlong_disjoint_arraycopy;
177   static address _oop_disjoint_arraycopy, _oop_disjoint_arraycopy_uninit;
178 
179   // arraycopy operands aligned on zero'th element boundary
180   // These are identical to the ones aligned aligned on an
181   // element type boundary, except that they assume that both
182   // source and destination are HeapWord aligned.
183   static address _arrayof_jbyte_arraycopy;
184   static address _arrayof_jshort_arraycopy;
185   static address _arrayof_jint_arraycopy;
186   static address _arrayof_jlong_arraycopy;
187   static address _arrayof_oop_arraycopy, _arrayof_oop_arraycopy_uninit;
188   static address _arrayof_jbyte_disjoint_arraycopy;
189   static address _arrayof_jshort_disjoint_arraycopy;
190   static address _arrayof_jint_disjoint_arraycopy;
191   static address _arrayof_jlong_disjoint_arraycopy;
192   static address _arrayof_oop_disjoint_arraycopy, _arrayof_oop_disjoint_arraycopy_uninit;
193 
194   // cache line writeback
195   static address _data_cache_writeback;
196   static address _data_cache_writeback_sync;
197 
198   // these are recommended but optional:
199   static address _checkcast_arraycopy, _checkcast_arraycopy_uninit;
200   static address _unsafe_arraycopy;
201   static address _generic_arraycopy;
202 
203   static address _jbyte_fill;
204   static address _jshort_fill;
205   static address _jint_fill;
206   static address _arrayof_jbyte_fill;
207   static address _arrayof_jshort_fill;
208   static address _arrayof_jint_fill;
209 
210   // zero heap space aligned to jlong (8 bytes)
211   static address _zero_aligned_words;
212 
213   static address _aescrypt_encryptBlock;
214   static address _aescrypt_decryptBlock;
215   static address _cipherBlockChaining_encryptAESCrypt;
216   static address _cipherBlockChaining_decryptAESCrypt;
217   static address _electronicCodeBook_encryptAESCrypt;
218   static address _electronicCodeBook_decryptAESCrypt;
219   static address _counterMode_AESCrypt;
220   static address _ghash_processBlocks;
221   static address _base64_encodeBlock;
222 
223   static address _sha1_implCompress;
224   static address _sha1_implCompressMB;
225   static address _sha256_implCompress;
226   static address _sha256_implCompressMB;
227   static address _sha512_implCompress;
228   static address _sha512_implCompressMB;
229 
230   static address _updateBytesCRC32;
231   static address _crc_table_adr;
232 
233   static address _crc32c_table_addr;
234   static address _updateBytesCRC32C;
235   static address _updateBytesAdler32;
236 
237   static address _multiplyToLen;
238   static address _squareToLen;
239   static address _mulAdd;
240   static address _montgomeryMultiply;
241   static address _montgomerySquare;
242   static address _bigIntegerRightShiftWorker;
243   static address _bigIntegerLeftShiftWorker;
244 
245   static address _vectorizedMismatch;
246 
247   static address _dexp;
248   static address _dlog;
249   static address _dlog10;
250   static address _dpow;
251   static address _dsin;
252   static address _dcos;
253   static address _dlibm_sin_cos_huge;
254   static address _dlibm_reduce_pi04l;
255   static address _dlibm_tan_cot_huge;
256   static address _dtan;
257 
258   // Safefetch stubs.
259   static address _safefetch32_entry;
260   static address _safefetch32_fault_pc;
261   static address _safefetch32_continuation_pc;
262   static address _safefetchN_entry;
263   static address _safefetchN_fault_pc;
264   static address _safefetchN_continuation_pc;
265 
266  public:
267   // Initialization/Testing
268   static void    initialize1();                            // must happen before universe::genesis
269   static void    initialize2();                            // must happen after  universe::genesis
270 
271   static bool is_stub_code(address addr)                   { return contains(addr); }
272 
273   static bool contains(address addr) {
274     return
275       (_code1 != NULL && _code1->blob_contains(addr)) ||
276       (_code2 != NULL && _code2->blob_contains(addr)) ;
277   }
278 
279   static RuntimeBlob* code1() { return _code1; }
280   static RuntimeBlob* code2() { return _code2; }
281 
282   // Debugging
283   static jint    verify_oop_count()                        { return _verify_oop_count; }
284   static jint*   verify_oop_count_addr()                   { return &_verify_oop_count; }
285   // a subroutine for debugging the GC
286   static address verify_oop_subroutine_entry_address()     { return (address)&_verify_oop_subroutine_entry; }
287 
288   static address catch_exception_entry()                   { return _catch_exception_entry; }
289 
290   // Calls to Java
291   typedef void (*CallStub)(
292     address   link,
293     intptr_t* result,
294     BasicType result_type,
295     Method* method,
296     address   entry_point,
297     intptr_t* parameters,
298     int       size_of_parameters,
299     TRAPS
300   );
301 
302   static CallStub call_stub()                              { return CAST_TO_FN_PTR(CallStub, _call_stub_entry); }
303 
304   // Exceptions
305   static address forward_exception_entry()                 { return _forward_exception_entry; }
306   // Implicit exceptions
307   static address throw_AbstractMethodError_entry()         { return _throw_AbstractMethodError_entry; }
308   static address throw_IncompatibleClassChangeError_entry(){ return _throw_IncompatibleClassChangeError_entry; }
309   static address throw_NullPointerException_at_call_entry(){ return _throw_NullPointerException_at_call_entry; }
310   static address throw_StackOverflowError_entry()          { return _throw_StackOverflowError_entry; }
311   static address throw_delayed_StackOverflowError_entry()  { return _throw_delayed_StackOverflowError_entry; }
312 
313   static address atomic_xchg_entry()                       { return _atomic_xchg_entry; }
314   static address atomic_xchg_long_entry()                  { return _atomic_xchg_long_entry; }
315   static address atomic_store_entry()                      { return _atomic_store_entry; }
316   static address atomic_cmpxchg_entry()                    { return _atomic_cmpxchg_entry; }
317   static address atomic_cmpxchg_byte_entry()               { return _atomic_cmpxchg_byte_entry; }
318   static address atomic_cmpxchg_long_entry()               { return _atomic_cmpxchg_long_entry; }
319   static address atomic_add_entry()                        { return _atomic_add_entry; }
320   static address atomic_add_long_entry()                   { return _atomic_add_long_entry; }
321   static address fence_entry()                             { return _fence_entry; }
322 
323   static address d2i_wrapper()                             { return _d2i_wrapper; }
324   static address d2l_wrapper()                             { return _d2l_wrapper; }
325   static jint    fpu_cntrl_wrd_std()                       { return _fpu_cntrl_wrd_std;   }
326   static address addr_fpu_cntrl_wrd_std()                  { return (address)&_fpu_cntrl_wrd_std;   }
327   static address addr_fpu_cntrl_wrd_24()                   { return (address)&_fpu_cntrl_wrd_24;   }
328   static address addr_fpu_cntrl_wrd_trunc()                { return (address)&_fpu_cntrl_wrd_trunc; }
329   static address addr_mxcsr_std()                          { return (address)&_mxcsr_std; }
330   static address addr_fpu_subnormal_bias1()                { return (address)&_fpu_subnormal_bias1; }
331   static address addr_fpu_subnormal_bias2()                { return (address)&_fpu_subnormal_bias2; }
332 
333 
334   static address select_arraycopy_function(BasicType t, bool aligned, bool disjoint, const char* &name, bool dest_uninitialized);
335 
336   static address jbyte_arraycopy()  { return _jbyte_arraycopy; }
337   static address jshort_arraycopy() { return _jshort_arraycopy; }
338   static address jint_arraycopy()   { return _jint_arraycopy; }
339   static address jlong_arraycopy()  { return _jlong_arraycopy; }
340   static address oop_arraycopy(bool dest_uninitialized = false) {
341     return dest_uninitialized ? _oop_arraycopy_uninit : _oop_arraycopy;
342   }
343   static address jbyte_disjoint_arraycopy()  { return _jbyte_disjoint_arraycopy; }
344   static address jshort_disjoint_arraycopy() { return _jshort_disjoint_arraycopy; }
345   static address jint_disjoint_arraycopy()   { return _jint_disjoint_arraycopy; }
346   static address jlong_disjoint_arraycopy()  { return _jlong_disjoint_arraycopy; }
347   static address oop_disjoint_arraycopy(bool dest_uninitialized = false) {
348     return dest_uninitialized ?  _oop_disjoint_arraycopy_uninit : _oop_disjoint_arraycopy;
349   }
350 
351   static address arrayof_jbyte_arraycopy()  { return _arrayof_jbyte_arraycopy; }
352   static address arrayof_jshort_arraycopy() { return _arrayof_jshort_arraycopy; }
353   static address arrayof_jint_arraycopy()   { return _arrayof_jint_arraycopy; }
354   static address arrayof_jlong_arraycopy()  { return _arrayof_jlong_arraycopy; }
355   static address arrayof_oop_arraycopy(bool dest_uninitialized = false) {
356     return dest_uninitialized ? _arrayof_oop_arraycopy_uninit : _arrayof_oop_arraycopy;
357   }
358 
359   static address arrayof_jbyte_disjoint_arraycopy()  { return _arrayof_jbyte_disjoint_arraycopy; }
360   static address arrayof_jshort_disjoint_arraycopy() { return _arrayof_jshort_disjoint_arraycopy; }
361   static address arrayof_jint_disjoint_arraycopy()   { return _arrayof_jint_disjoint_arraycopy; }
362   static address arrayof_jlong_disjoint_arraycopy()  { return _arrayof_jlong_disjoint_arraycopy; }
363   static address arrayof_oop_disjoint_arraycopy(bool dest_uninitialized = false) {
364     return dest_uninitialized ? _arrayof_oop_disjoint_arraycopy_uninit : _arrayof_oop_disjoint_arraycopy;
365   }
366   static address data_cache_writeback()              { return _data_cache_writeback; }
367   static address data_cache_writeback_sync()         { return _data_cache_writeback_sync; }
368 
369   typedef void (*DataCacheWritebackStub)(void *);
370   static DataCacheWritebackStub DataCacheWriteback_stub()         { return CAST_TO_FN_PTR(DataCacheWritebackStub,  _data_cache_writeback); }
371   typedef void (*DataCacheWritebackSyncStub)(bool);
372   static DataCacheWritebackSyncStub DataCacheWritebackSync_stub() { return CAST_TO_FN_PTR(DataCacheWritebackSyncStub,  _data_cache_writeback_sync); }
373 
374   static address checkcast_arraycopy(bool dest_uninitialized = false) {
375     return dest_uninitialized ? _checkcast_arraycopy_uninit : _checkcast_arraycopy;
376   }
377   static address unsafe_arraycopy()     { return _unsafe_arraycopy; }
378 
379   typedef void (*UnsafeArrayCopyStub)(const void* src, void* dst, size_t count);
380   static UnsafeArrayCopyStub UnsafeArrayCopy_stub()         { return CAST_TO_FN_PTR(UnsafeArrayCopyStub,  _unsafe_arraycopy); }
381 
382   static address generic_arraycopy()   { return _generic_arraycopy; }
383 
384   static address jbyte_fill()          { return _jbyte_fill; }
385   static address jshort_fill()         { return _jshort_fill; }
386   static address jint_fill()           { return _jint_fill; }
387   static address arrayof_jbyte_fill()  { return _arrayof_jbyte_fill; }
388   static address arrayof_jshort_fill() { return _arrayof_jshort_fill; }
389   static address arrayof_jint_fill()   { return _arrayof_jint_fill; }
390 
391   static address aescrypt_encryptBlock()                { return _aescrypt_encryptBlock; }
392   static address aescrypt_decryptBlock()                { return _aescrypt_decryptBlock; }
393   static address cipherBlockChaining_encryptAESCrypt()  { return _cipherBlockChaining_encryptAESCrypt; }
394   static address cipherBlockChaining_decryptAESCrypt()  { return _cipherBlockChaining_decryptAESCrypt; }
395   static address electronicCodeBook_encryptAESCrypt()   { return _electronicCodeBook_encryptAESCrypt; }
396   static address electronicCodeBook_decryptAESCrypt()   { return _electronicCodeBook_decryptAESCrypt; }
397   static address counterMode_AESCrypt()  { return _counterMode_AESCrypt; }
398   static address ghash_processBlocks()   { return _ghash_processBlocks; }
399   static address base64_encodeBlock()    { return _base64_encodeBlock; }
400   static address sha1_implCompress()     { return _sha1_implCompress; }
401   static address sha1_implCompressMB()   { return _sha1_implCompressMB; }
402   static address sha256_implCompress()   { return _sha256_implCompress; }
403   static address sha256_implCompressMB() { return _sha256_implCompressMB; }
404   static address sha512_implCompress()   { return _sha512_implCompress; }
405   static address sha512_implCompressMB() { return _sha512_implCompressMB; }
406 
407   static address updateBytesCRC32()    { return _updateBytesCRC32; }
408   static address crc_table_addr()      { return _crc_table_adr; }
409 
410   static address crc32c_table_addr()   { return _crc32c_table_addr; }
411   static address updateBytesCRC32C()   { return _updateBytesCRC32C; }
412   static address updateBytesAdler32()  { return _updateBytesAdler32; }
413 
414   static address multiplyToLen()       { return _multiplyToLen; }
415   static address squareToLen()         { return _squareToLen; }
416   static address mulAdd()              { return _mulAdd; }
417   static address montgomeryMultiply()  { return _montgomeryMultiply; }
418   static address montgomerySquare()    { return _montgomerySquare; }
419   static address bigIntegerRightShift() { return _bigIntegerRightShiftWorker; }
420   static address bigIntegerLeftShift()  { return _bigIntegerLeftShiftWorker; }
421 
422   static address vectorizedMismatch()  { return _vectorizedMismatch; }
423 
424   static address dexp()                { return _dexp; }
425   static address dlog()                { return _dlog; }
426   static address dlog10()              { return _dlog10; }
427   static address dpow()                { return _dpow; }
428   static address dsin()                { return _dsin; }
429   static address dcos()                { return _dcos; }
430   static address dlibm_reduce_pi04l()  { return _dlibm_reduce_pi04l; }
431   static address dlibm_sin_cos_huge()  { return _dlibm_sin_cos_huge; }
432   static address dlibm_tan_cot_huge()  { return _dlibm_tan_cot_huge; }
433   static address dtan()                { return _dtan; }
434 
435   static address select_fill_function(BasicType t, bool aligned, const char* &name);
436 
437   static address zero_aligned_words()  { return _zero_aligned_words; }
438 
439   //
440   // Safefetch stub support
441   //
442 
443   typedef int      (*SafeFetch32Stub)(int*      adr, int      errValue);
444   typedef intptr_t (*SafeFetchNStub) (intptr_t* adr, intptr_t errValue);
445 
446   static SafeFetch32Stub SafeFetch32_stub() { return CAST_TO_FN_PTR(SafeFetch32Stub, _safefetch32_entry); }
447   static SafeFetchNStub  SafeFetchN_stub()  { return CAST_TO_FN_PTR(SafeFetchNStub,  _safefetchN_entry); }
448 
449   static bool is_safefetch_fault(address pc) {
450     return pc != NULL &&
451           (pc == _safefetch32_fault_pc ||
452            pc == _safefetchN_fault_pc);
453   }
454 
455   static address continuation_for_safefetch_fault(address pc) {
456     assert(_safefetch32_continuation_pc != NULL &&
457            _safefetchN_continuation_pc  != NULL,
458            "not initialized");
459 
460     if (pc == _safefetch32_fault_pc) return _safefetch32_continuation_pc;
461     if (pc == _safefetchN_fault_pc)  return _safefetchN_continuation_pc;
462 
463     ShouldNotReachHere();
464     return NULL;
465   }
466 
467   //
468   // Default versions of the above arraycopy functions for platforms which do
469   // not have specialized versions
470   //
471   static void jbyte_copy     (jbyte*  src, jbyte*  dest, size_t count);
472   static void jshort_copy    (jshort* src, jshort* dest, size_t count);
473   static void jint_copy      (jint*   src, jint*   dest, size_t count);
474   static void jlong_copy     (jlong*  src, jlong*  dest, size_t count);
475   static void oop_copy       (oop*    src, oop*    dest, size_t count);
476   static void oop_copy_uninit(oop*    src, oop*    dest, size_t count);
477 
478   static void arrayof_jbyte_copy     (HeapWord* src, HeapWord* dest, size_t count);
479   static void arrayof_jshort_copy    (HeapWord* src, HeapWord* dest, size_t count);
480   static void arrayof_jint_copy      (HeapWord* src, HeapWord* dest, size_t count);
481   static void arrayof_jlong_copy     (HeapWord* src, HeapWord* dest, size_t count);
482   static void arrayof_oop_copy       (HeapWord* src, HeapWord* dest, size_t count);
483   static void arrayof_oop_copy_uninit(HeapWord* src, HeapWord* dest, size_t count);
484 };
485 
486 // Safefetch allows to load a value from a location that's not known
487 // to be valid. If the load causes a fault, the error value is returned.
488 inline int SafeFetch32(int* adr, int errValue) {
489   assert(StubRoutines::SafeFetch32_stub(), "stub not yet generated");
490   return StubRoutines::SafeFetch32_stub()(adr, errValue);
491 }
492 inline intptr_t SafeFetchN(intptr_t* adr, intptr_t errValue) {
493   assert(StubRoutines::SafeFetchN_stub(), "stub not yet generated");
494   return StubRoutines::SafeFetchN_stub()(adr, errValue);
495 }
496 
497 
498 // returns true if SafeFetch32 and SafeFetchN can be used safely (stubroutines are already generated)
499 inline bool CanUseSafeFetch32() {
500   return StubRoutines::SafeFetch32_stub() ? true : false;
501 }
502 
503 inline bool CanUseSafeFetchN() {
504   return StubRoutines::SafeFetchN_stub() ? true : false;
505 }
506 #endif // SHARE_RUNTIME_STUBROUTINES_HPP