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   // these are recommended but optional:
 195   static address _checkcast_arraycopy, _checkcast_arraycopy_uninit;
 196   static address _unsafe_arraycopy;
 197   static address _generic_arraycopy;
 198 
 199   static address _jbyte_fill;
 200   static address _jshort_fill;
 201   static address _jint_fill;
 202   static address _arrayof_jbyte_fill;
 203   static address _arrayof_jshort_fill;
 204   static address _arrayof_jint_fill;
 205 
 206   // zero heap space aligned to jlong (8 bytes)
 207   static address _zero_aligned_words;
 208 
 209   static address _aescrypt_encryptBlock;
 210   static address _aescrypt_decryptBlock;
 211   static address _cipherBlockChaining_encryptAESCrypt;
 212   static address _cipherBlockChaining_decryptAESCrypt;
 213   static address _counterMode_AESCrypt;
 214   static address _ghash_processBlocks;
 215   static address _base64_encodeBlock;
 216 
 217   static address _sha1_implCompress;
 218   static address _sha1_implCompressMB;
 219   static address _sha256_implCompress;
 220   static address _sha256_implCompressMB;
 221   static address _sha512_implCompress;
 222   static address _sha512_implCompressMB;
 223 
 224   static address _updateBytesCRC32;
 225   static address _crc_table_adr;
 226 
 227   static address _crc32c_table_addr;
 228   static address _updateBytesCRC32C;
 229   static address _updateBytesAdler32;
 230 
 231   static address _multiplyToLen;
 232   static address _squareToLen;
 233   static address _mulAdd;
 234   static address _montgomeryMultiply;
 235   static address _montgomerySquare;
 236 
 237   static address _vectorizedMismatch;
 238 
 239   static address _dexp;
 240   static address _dlog;
 241   static address _dlog10;
 242   static address _dpow;
 243   static address _dsin;
 244   static address _dcos;
 245   static address _dlibm_sin_cos_huge;
 246   static address _dlibm_reduce_pi04l;
 247   static address _dlibm_tan_cot_huge;
 248   static address _dtan;
 249 
 250   // Safefetch stubs.
 251   static address _safefetch32_entry;
 252   static address _safefetch32_fault_pc;
 253   static address _safefetch32_continuation_pc;
 254   static address _safefetchN_entry;
 255   static address _safefetchN_fault_pc;
 256   static address _safefetchN_continuation_pc;
 257 
 258  public:
 259   // Initialization/Testing
 260   static void    initialize1();                            // must happen before universe::genesis
 261   static void    initialize2();                            // must happen after  universe::genesis
 262 
 263   static bool is_stub_code(address addr)                   { return contains(addr); }
 264 
 265   static bool contains(address addr) {
 266     return
 267       (_code1 != NULL && _code1->blob_contains(addr)) ||
 268       (_code2 != NULL && _code2->blob_contains(addr)) ;
 269   }
 270 
 271   static RuntimeBlob* code1() { return _code1; }
 272   static RuntimeBlob* code2() { return _code2; }
 273 
 274   // Debugging
 275   static jint    verify_oop_count()                        { return _verify_oop_count; }
 276   static jint*   verify_oop_count_addr()                   { return &_verify_oop_count; }
 277   // a subroutine for debugging the GC
 278   static address verify_oop_subroutine_entry_address()     { return (address)&_verify_oop_subroutine_entry; }
 279 
 280   static address catch_exception_entry()                   { return _catch_exception_entry; }
 281 
 282   // Calls to Java
 283   typedef void (*CallStub)(
 284     address   link,
 285     intptr_t* result,
 286     BasicType result_type,
 287     Method* method,
 288     address   entry_point,
 289     intptr_t* parameters,
 290     int       size_of_parameters,
 291     TRAPS
 292   );
 293 
 294   static CallStub call_stub()                              { return CAST_TO_FN_PTR(CallStub, _call_stub_entry); }
 295 
 296   // Exceptions
 297   static address forward_exception_entry()                 { return _forward_exception_entry; }
 298   // Implicit exceptions
 299   static address throw_AbstractMethodError_entry()         { return _throw_AbstractMethodError_entry; }
 300   static address throw_IncompatibleClassChangeError_entry(){ return _throw_IncompatibleClassChangeError_entry; }
 301   static address throw_NullPointerException_at_call_entry(){ return _throw_NullPointerException_at_call_entry; }
 302   static address throw_StackOverflowError_entry()          { return _throw_StackOverflowError_entry; }
 303   static address throw_delayed_StackOverflowError_entry()  { return _throw_delayed_StackOverflowError_entry; }
 304 
 305   static address atomic_xchg_entry()                       { return _atomic_xchg_entry; }
 306   static address atomic_xchg_long_entry()                  { return _atomic_xchg_long_entry; }
 307   static address atomic_store_entry()                      { return _atomic_store_entry; }
 308   static address atomic_cmpxchg_entry()                    { return _atomic_cmpxchg_entry; }
 309   static address atomic_cmpxchg_byte_entry()               { return _atomic_cmpxchg_byte_entry; }
 310   static address atomic_cmpxchg_long_entry()               { return _atomic_cmpxchg_long_entry; }
 311   static address atomic_add_entry()                        { return _atomic_add_entry; }
 312   static address atomic_add_long_entry()                   { return _atomic_add_long_entry; }
 313   static address fence_entry()                             { return _fence_entry; }
 314 
 315   static address d2i_wrapper()                             { return _d2i_wrapper; }
 316   static address d2l_wrapper()                             { return _d2l_wrapper; }
 317   static jint    fpu_cntrl_wrd_std()                       { return _fpu_cntrl_wrd_std;   }
 318   static address addr_fpu_cntrl_wrd_std()                  { return (address)&_fpu_cntrl_wrd_std;   }
 319   static address addr_fpu_cntrl_wrd_24()                   { return (address)&_fpu_cntrl_wrd_24;   }
 320   static address addr_fpu_cntrl_wrd_trunc()                { return (address)&_fpu_cntrl_wrd_trunc; }
 321   static address addr_mxcsr_std()                          { return (address)&_mxcsr_std; }
 322   static address addr_fpu_subnormal_bias1()                { return (address)&_fpu_subnormal_bias1; }
 323   static address addr_fpu_subnormal_bias2()                { return (address)&_fpu_subnormal_bias2; }
 324 
 325 
 326   static address select_arraycopy_function(BasicType t, bool aligned, bool disjoint, const char* &name, bool dest_uninitialized);
 327 
 328   static address jbyte_arraycopy()  { return _jbyte_arraycopy; }
 329   static address jshort_arraycopy() { return _jshort_arraycopy; }
 330   static address jint_arraycopy()   { return _jint_arraycopy; }
 331   static address jlong_arraycopy()  { return _jlong_arraycopy; }
 332   static address oop_arraycopy(bool dest_uninitialized = false) {
 333     return dest_uninitialized ? _oop_arraycopy_uninit : _oop_arraycopy;
 334   }
 335   static address jbyte_disjoint_arraycopy()  { return _jbyte_disjoint_arraycopy; }
 336   static address jshort_disjoint_arraycopy() { return _jshort_disjoint_arraycopy; }
 337   static address jint_disjoint_arraycopy()   { return _jint_disjoint_arraycopy; }
 338   static address jlong_disjoint_arraycopy()  { return _jlong_disjoint_arraycopy; }
 339   static address oop_disjoint_arraycopy(bool dest_uninitialized = false) {
 340     return dest_uninitialized ?  _oop_disjoint_arraycopy_uninit : _oop_disjoint_arraycopy;
 341   }
 342 
 343   static address arrayof_jbyte_arraycopy()  { return _arrayof_jbyte_arraycopy; }
 344   static address arrayof_jshort_arraycopy() { return _arrayof_jshort_arraycopy; }
 345   static address arrayof_jint_arraycopy()   { return _arrayof_jint_arraycopy; }
 346   static address arrayof_jlong_arraycopy()  { return _arrayof_jlong_arraycopy; }
 347   static address arrayof_oop_arraycopy(bool dest_uninitialized = false) {
 348     return dest_uninitialized ? _arrayof_oop_arraycopy_uninit : _arrayof_oop_arraycopy;
 349   }
 350 
 351   static address arrayof_jbyte_disjoint_arraycopy()  { return _arrayof_jbyte_disjoint_arraycopy; }
 352   static address arrayof_jshort_disjoint_arraycopy() { return _arrayof_jshort_disjoint_arraycopy; }
 353   static address arrayof_jint_disjoint_arraycopy()   { return _arrayof_jint_disjoint_arraycopy; }
 354   static address arrayof_jlong_disjoint_arraycopy()  { return _arrayof_jlong_disjoint_arraycopy; }
 355   static address arrayof_oop_disjoint_arraycopy(bool dest_uninitialized = false) {
 356     return dest_uninitialized ? _arrayof_oop_disjoint_arraycopy_uninit : _arrayof_oop_disjoint_arraycopy;
 357   }
 358   static address checkcast_arraycopy(bool dest_uninitialized = false) {
 359     return dest_uninitialized ? _checkcast_arraycopy_uninit : _checkcast_arraycopy;
 360   }
 361   static address unsafe_arraycopy()     { return _unsafe_arraycopy; }
 362 
 363   typedef void (*UnsafeArrayCopyStub)(const void* src, void* dst, size_t count);
 364   static UnsafeArrayCopyStub UnsafeArrayCopy_stub()         { return CAST_TO_FN_PTR(UnsafeArrayCopyStub,  _unsafe_arraycopy); }
 365 
 366   static address generic_arraycopy()   { return _generic_arraycopy; }
 367 
 368   static address jbyte_fill()          { return _jbyte_fill; }
 369   static address jshort_fill()         { return _jshort_fill; }
 370   static address jint_fill()           { return _jint_fill; }
 371   static address arrayof_jbyte_fill()  { return _arrayof_jbyte_fill; }
 372   static address arrayof_jshort_fill() { return _arrayof_jshort_fill; }
 373   static address arrayof_jint_fill()   { return _arrayof_jint_fill; }
 374 
 375   static address aescrypt_encryptBlock()                { return _aescrypt_encryptBlock; }
 376   static address aescrypt_decryptBlock()                { return _aescrypt_decryptBlock; }
 377   static address cipherBlockChaining_encryptAESCrypt()  { return _cipherBlockChaining_encryptAESCrypt; }
 378   static address cipherBlockChaining_decryptAESCrypt()  { return _cipherBlockChaining_decryptAESCrypt; }
 379   static address counterMode_AESCrypt()  { return _counterMode_AESCrypt; }
 380   static address ghash_processBlocks()   { return _ghash_processBlocks; }
 381   static address base64_encodeBlock()    { return _base64_encodeBlock; }
 382   static address sha1_implCompress()     { return _sha1_implCompress; }
 383   static address sha1_implCompressMB()   { return _sha1_implCompressMB; }
 384   static address sha256_implCompress()   { return _sha256_implCompress; }
 385   static address sha256_implCompressMB() { return _sha256_implCompressMB; }
 386   static address sha512_implCompress()   { return _sha512_implCompress; }
 387   static address sha512_implCompressMB() { return _sha512_implCompressMB; }
 388 
 389   static address updateBytesCRC32()    { return _updateBytesCRC32; }
 390   static address crc_table_addr()      { return _crc_table_adr; }
 391 
 392   static address crc32c_table_addr()   { return _crc32c_table_addr; }
 393   static address updateBytesCRC32C()   { return _updateBytesCRC32C; }
 394   static address updateBytesAdler32()  { return _updateBytesAdler32; }
 395 
 396   static address multiplyToLen()       { return _multiplyToLen; }
 397   static address squareToLen()         { return _squareToLen; }
 398   static address mulAdd()              { return _mulAdd; }
 399   static address montgomeryMultiply()  { return _montgomeryMultiply; }
 400   static address montgomerySquare()    { return _montgomerySquare; }
 401 
 402   static address vectorizedMismatch()  { return _vectorizedMismatch; }
 403 
 404   static address dexp()                { return _dexp; }
 405   static address dlog()                { return _dlog; }
 406   static address dlog10()              { return _dlog10; }
 407   static address dpow()                { return _dpow; }
 408   static address dsin()                { return _dsin; }
 409   static address dcos()                { return _dcos; }
 410   static address dlibm_reduce_pi04l()  { return _dlibm_reduce_pi04l; }
 411   static address dlibm_sin_cos_huge()  { return _dlibm_sin_cos_huge; }
 412   static address dlibm_tan_cot_huge()  { return _dlibm_tan_cot_huge; }
 413   static address dtan()                { return _dtan; }
 414 
 415   static address select_fill_function(BasicType t, bool aligned, const char* &name);
 416 
 417   static address zero_aligned_words()  { return _zero_aligned_words; }
 418 
 419   //
 420   // Safefetch stub support
 421   //
 422 
 423   typedef int      (*SafeFetch32Stub)(int*      adr, int      errValue);
 424   typedef intptr_t (*SafeFetchNStub) (intptr_t* adr, intptr_t errValue);
 425 
 426   static SafeFetch32Stub SafeFetch32_stub() { return CAST_TO_FN_PTR(SafeFetch32Stub, _safefetch32_entry); }
 427   static SafeFetchNStub  SafeFetchN_stub()  { return CAST_TO_FN_PTR(SafeFetchNStub,  _safefetchN_entry); }
 428 
 429   static bool is_safefetch_fault(address pc) {
 430     return pc != NULL &&
 431           (pc == _safefetch32_fault_pc ||
 432            pc == _safefetchN_fault_pc);
 433   }
 434 
 435   static address continuation_for_safefetch_fault(address pc) {
 436     assert(_safefetch32_continuation_pc != NULL &&
 437            _safefetchN_continuation_pc  != NULL,
 438            "not initialized");
 439 
 440     if (pc == _safefetch32_fault_pc) return _safefetch32_continuation_pc;
 441     if (pc == _safefetchN_fault_pc)  return _safefetchN_continuation_pc;
 442 
 443     ShouldNotReachHere();
 444     return NULL;
 445   }
 446 
 447   //
 448   // Default versions of the above arraycopy functions for platforms which do
 449   // not have specialized versions
 450   //
 451   static void jbyte_copy     (jbyte*  src, jbyte*  dest, size_t count);
 452   static void jshort_copy    (jshort* src, jshort* dest, size_t count);
 453   static void jint_copy      (jint*   src, jint*   dest, size_t count);
 454   static void jlong_copy     (jlong*  src, jlong*  dest, size_t count);
 455   static void oop_copy       (oop*    src, oop*    dest, size_t count);
 456   static void oop_copy_uninit(oop*    src, oop*    dest, size_t count);
 457 
 458   static void arrayof_jbyte_copy     (HeapWord* src, HeapWord* dest, size_t count);
 459   static void arrayof_jshort_copy    (HeapWord* src, HeapWord* dest, size_t count);
 460   static void arrayof_jint_copy      (HeapWord* src, HeapWord* dest, size_t count);
 461   static void arrayof_jlong_copy     (HeapWord* src, HeapWord* dest, size_t count);
 462   static void arrayof_oop_copy       (HeapWord* src, HeapWord* dest, size_t count);
 463   static void arrayof_oop_copy_uninit(HeapWord* src, HeapWord* dest, size_t count);
 464 };
 465 
 466 // Safefetch allows to load a value from a location that's not known
 467 // to be valid. If the load causes a fault, the error value is returned.
 468 inline int SafeFetch32(int* adr, int errValue) {
 469   assert(StubRoutines::SafeFetch32_stub(), "stub not yet generated");
 470   return StubRoutines::SafeFetch32_stub()(adr, errValue);
 471 }
 472 inline intptr_t SafeFetchN(intptr_t* adr, intptr_t errValue) {
 473   assert(StubRoutines::SafeFetchN_stub(), "stub not yet generated");
 474   return StubRoutines::SafeFetchN_stub()(adr, errValue);
 475 }
 476 
 477 
 478 // returns true if SafeFetch32 and SafeFetchN can be used safely (stubroutines are already generated)
 479 inline bool CanUseSafeFetch32() {
 480   return StubRoutines::SafeFetch32_stub() ? true : false;
 481 }
 482 
 483 inline bool CanUseSafeFetchN() {
 484   return StubRoutines::SafeFetchN_stub() ? true : false;
 485 }
 486 #endif // SHARE_RUNTIME_STUBROUTINES_HPP