1 /*
   2  * Copyright (c) 1999, 2010, 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 // no precompiled headers
  26 #include "assembler_x86.inline.hpp"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "code/icBuffer.hpp"
  31 #include "code/vtableStubs.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "jvm_windows.h"
  34 #include "memory/allocation.inline.hpp"
  35 #include "mutex_windows.inline.hpp"
  36 #include "nativeInst_x86.hpp"
  37 #include "os_share_windows.hpp"
  38 #include "prims/jniFastGetField.hpp"
  39 #include "prims/jvm.h"
  40 #include "prims/jvm_misc.hpp"
  41 #include "runtime/arguments.hpp"
  42 #include "runtime/extendedPC.hpp"
  43 #include "runtime/frame.inline.hpp"
  44 #include "runtime/interfaceSupport.hpp"
  45 #include "runtime/java.hpp"
  46 #include "runtime/javaCalls.hpp"
  47 #include "runtime/mutexLocker.hpp"
  48 #include "runtime/osThread.hpp"
  49 #include "runtime/sharedRuntime.hpp"
  50 #include "runtime/stubRoutines.hpp"
  51 #include "runtime/timer.hpp"
  52 #include "thread_windows.inline.hpp"
  53 #include "utilities/events.hpp"
  54 #include "utilities/vmError.hpp"
  55 #ifdef COMPILER1
  56 #include "c1/c1_Runtime1.hpp"
  57 #endif
  58 #ifdef COMPILER2
  59 #include "opto/runtime.hpp"
  60 #endif
  61 
  62 # include "unwind_windows_x86.hpp"
  63 #undef REG_SP
  64 #undef REG_FP
  65 #undef REG_PC
  66 #ifdef AMD64
  67 #define REG_SP Rsp
  68 #define REG_FP Rbp
  69 #define REG_PC Rip
  70 #else
  71 #define REG_SP Esp
  72 #define REG_FP Ebp
  73 #define REG_PC Eip
  74 #endif // AMD64
  75 
  76 extern LONG WINAPI topLevelExceptionFilter(_EXCEPTION_POINTERS* );
  77 
  78 // Install a win32 structured exception handler around thread.
  79 void os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread) {
  80   __try {
  81 
  82 #ifndef AMD64
  83     // We store the current thread in this wrapperthread location
  84     // and determine how far away this address is from the structured
  85     // execption pointer that FS:[0] points to.  This get_thread
  86     // code can then get the thread pointer via FS.
  87     //
  88     // Warning:  This routine must NEVER be inlined since we'd end up with
  89     //           multiple offsets.
  90     //
  91     volatile Thread* wrapperthread = thread;
  92 
  93     if ( ThreadLocalStorage::get_thread_ptr_offset() == 0 ) {
  94       int thread_ptr_offset;
  95       __asm {
  96         lea eax, dword ptr wrapperthread;
  97         sub eax, dword ptr FS:[0H];
  98         mov thread_ptr_offset, eax
  99       };
 100       ThreadLocalStorage::set_thread_ptr_offset(thread_ptr_offset);
 101     }
 102 #ifdef ASSERT
 103     // Verify that the offset hasn't changed since we initally captured
 104     // it. This might happen if we accidentally ended up with an
 105     // inlined version of this routine.
 106     else {
 107       int test_thread_ptr_offset;
 108       __asm {
 109         lea eax, dword ptr wrapperthread;
 110         sub eax, dword ptr FS:[0H];
 111         mov test_thread_ptr_offset, eax
 112       };
 113       assert(test_thread_ptr_offset == ThreadLocalStorage::get_thread_ptr_offset(),
 114              "thread pointer offset from SEH changed");
 115     }
 116 #endif // ASSERT
 117 #endif // !AMD64
 118 
 119     f(value, method, args, thread);
 120   } __except(topLevelExceptionFilter((_EXCEPTION_POINTERS*)_exception_info())) {
 121       // Nothing to do.
 122   }
 123 }
 124 
 125 #ifdef AMD64
 126 
 127 // This is the language specific handler for exceptions
 128 // originating from dynamically generated code.
 129 // We call the standard structured exception handler
 130 // We only expect Continued Execution since we cannot unwind
 131 // from generated code.
 132 LONG HandleExceptionFromCodeCache(
 133   IN PEXCEPTION_RECORD ExceptionRecord,
 134   IN ULONG64 EstablisherFrame,
 135   IN OUT PCONTEXT ContextRecord,
 136   IN OUT PDISPATCHER_CONTEXT DispatcherContext) {
 137   EXCEPTION_POINTERS ep;
 138   LONG result;
 139 
 140   ep.ExceptionRecord = ExceptionRecord;
 141   ep.ContextRecord = ContextRecord;
 142 
 143   result = topLevelExceptionFilter(&ep);
 144 
 145   // We better only get a CONTINUE_EXECUTION from our handler
 146   // since we don't have unwind information registered.
 147 
 148   guarantee( result == EXCEPTION_CONTINUE_EXECUTION,
 149              "Unexpected result from topLevelExceptionFilter");
 150 
 151   return(ExceptionContinueExecution);
 152 }
 153 
 154 
 155 // Structure containing the Windows Data Structures required
 156 // to register our Code Cache exception handler.
 157 // We put these in the CodeCache since the API requires
 158 // all addresses in these structures are relative to the Code
 159 // area registered with RtlAddFunctionTable.
 160 typedef struct {
 161   char ExceptionHandlerInstr[16];  // jmp HandleExceptionFromCodeCache
 162   RUNTIME_FUNCTION rt;
 163   UNWIND_INFO_EH_ONLY unw;
 164 } DynamicCodeData, *pDynamicCodeData;
 165 
 166 #endif // AMD64
 167 //
 168 // Register our CodeCache area with the OS so it will dispatch exceptions
 169 // to our topLevelExceptionFilter when we take an exception in our
 170 // dynamically generated code.
 171 //
 172 // Arguments:  low and high are the address of the full reserved
 173 // codeCache area
 174 //
 175 bool os::register_code_area(char *low, char *high) {
 176 #ifdef AMD64
 177 
 178   ResourceMark rm;
 179 
 180   pDynamicCodeData pDCD;
 181   PRUNTIME_FUNCTION prt;
 182   PUNWIND_INFO_EH_ONLY punwind;
 183 
 184   // If we are using Vectored Exceptions we don't need this registration
 185   if (UseVectoredExceptions) return true;
 186 
 187   BufferBlob* blob = BufferBlob::create("CodeCache Exception Handler", sizeof(DynamicCodeData));
 188   CodeBuffer cb(blob);
 189   MacroAssembler* masm = new MacroAssembler(&cb);
 190   pDCD = (pDynamicCodeData) masm->pc();
 191 
 192   masm->jump(ExternalAddress((address)&HandleExceptionFromCodeCache));
 193   masm->flush();
 194 
 195   // Create an Unwind Structure specifying no unwind info
 196   // other than an Exception Handler
 197   punwind = &pDCD->unw;
 198   punwind->Version = 1;
 199   punwind->Flags = UNW_FLAG_EHANDLER;
 200   punwind->SizeOfProlog = 0;
 201   punwind->CountOfCodes = 0;
 202   punwind->FrameRegister = 0;
 203   punwind->FrameOffset = 0;
 204   punwind->ExceptionHandler = (char *)(&(pDCD->ExceptionHandlerInstr[0])) -
 205                               (char*)low;
 206   punwind->ExceptionData[0] = 0;
 207 
 208   // This structure describes the covered dynamic code area.
 209   // Addresses are relative to the beginning on the code cache area
 210   prt = &pDCD->rt;
 211   prt->BeginAddress = 0;
 212   prt->EndAddress = (ULONG)(high - low);
 213   prt->UnwindData = ((char *)punwind - low);
 214 
 215   guarantee(RtlAddFunctionTable(prt, 1, (ULONGLONG)low),
 216             "Failed to register Dynamic Code Exception Handler with RtlAddFunctionTable");
 217 
 218 #endif // AMD64
 219   return true;
 220 }
 221 
 222 void os::initialize_thread(Thread* thr) {
 223 // Nothing to do.
 224 }
 225 
 226 // Atomics and Stub Functions
 227 
 228 typedef jint      xchg_func_t            (jint,     volatile jint*);
 229 typedef intptr_t  xchg_ptr_func_t        (intptr_t, volatile intptr_t*);
 230 typedef jint      cmpxchg_func_t         (jint,     volatile jint*,  jint);
 231 typedef jlong     cmpxchg_long_func_t    (jlong,    volatile jlong*, jlong);
 232 typedef jint      add_func_t             (jint,     volatile jint*);
 233 typedef intptr_t  add_ptr_func_t         (intptr_t, volatile intptr_t*);
 234 
 235 #ifdef AMD64
 236 
 237 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
 238   // try to use the stub:
 239   xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
 240 
 241   if (func != NULL) {
 242     os::atomic_xchg_func = func;
 243     return (*func)(exchange_value, dest);
 244   }
 245   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 246 
 247   jint old_value = *dest;
 248   *dest = exchange_value;
 249   return old_value;
 250 }
 251 
 252 intptr_t os::atomic_xchg_ptr_bootstrap(intptr_t exchange_value, volatile intptr_t* dest) {
 253   // try to use the stub:
 254   xchg_ptr_func_t* func = CAST_TO_FN_PTR(xchg_ptr_func_t*, StubRoutines::atomic_xchg_ptr_entry());
 255 
 256   if (func != NULL) {
 257     os::atomic_xchg_ptr_func = func;
 258     return (*func)(exchange_value, dest);
 259   }
 260   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 261 
 262   intptr_t old_value = *dest;
 263   *dest = exchange_value;
 264   return old_value;
 265 }
 266 
 267 
 268 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
 269   // try to use the stub:
 270   cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
 271 
 272   if (func != NULL) {
 273     os::atomic_cmpxchg_func = func;
 274     return (*func)(exchange_value, dest, compare_value);
 275   }
 276   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 277 
 278   jint old_value = *dest;
 279   if (old_value == compare_value)
 280     *dest = exchange_value;
 281   return old_value;
 282 }
 283 #endif // AMD64
 284 
 285 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
 286   // try to use the stub:
 287   cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
 288 
 289   if (func != NULL) {
 290     os::atomic_cmpxchg_long_func = func;
 291     return (*func)(exchange_value, dest, compare_value);
 292   }
 293   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 294 
 295   jlong old_value = *dest;
 296   if (old_value == compare_value)
 297     *dest = exchange_value;
 298   return old_value;
 299 }
 300 
 301 #ifdef AMD64
 302 
 303 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
 304   // try to use the stub:
 305   add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
 306 
 307   if (func != NULL) {
 308     os::atomic_add_func = func;
 309     return (*func)(add_value, dest);
 310   }
 311   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 312 
 313   return (*dest) += add_value;
 314 }
 315 
 316 intptr_t os::atomic_add_ptr_bootstrap(intptr_t add_value, volatile intptr_t* dest) {
 317   // try to use the stub:
 318   add_ptr_func_t* func = CAST_TO_FN_PTR(add_ptr_func_t*, StubRoutines::atomic_add_ptr_entry());
 319 
 320   if (func != NULL) {
 321     os::atomic_add_ptr_func = func;
 322     return (*func)(add_value, dest);
 323   }
 324   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 325 
 326   return (*dest) += add_value;
 327 }
 328 
 329 xchg_func_t*         os::atomic_xchg_func         = os::atomic_xchg_bootstrap;
 330 xchg_ptr_func_t*     os::atomic_xchg_ptr_func     = os::atomic_xchg_ptr_bootstrap;
 331 cmpxchg_func_t*      os::atomic_cmpxchg_func      = os::atomic_cmpxchg_bootstrap;
 332 add_func_t*          os::atomic_add_func          = os::atomic_add_bootstrap;
 333 add_ptr_func_t*      os::atomic_add_ptr_func      = os::atomic_add_ptr_bootstrap;
 334 
 335 #endif // AMD64
 336 
 337 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
 338 
 339 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
 340                     intptr_t** ret_sp, intptr_t** ret_fp) {
 341 
 342   ExtendedPC  epc;
 343   CONTEXT* uc = (CONTEXT*)ucVoid;
 344 
 345   if (uc != NULL) {
 346     epc = ExtendedPC((address)uc->REG_PC);
 347     if (ret_sp) *ret_sp = (intptr_t*)uc->REG_SP;
 348     if (ret_fp) *ret_fp = (intptr_t*)uc->REG_FP;
 349   } else {
 350     // construct empty ExtendedPC for return value checking
 351     epc = ExtendedPC(NULL);
 352     if (ret_sp) *ret_sp = (intptr_t *)NULL;
 353     if (ret_fp) *ret_fp = (intptr_t *)NULL;
 354   }
 355 
 356   return epc;
 357 }
 358 
 359 frame os::fetch_frame_from_context(void* ucVoid) {
 360   intptr_t* sp;
 361   intptr_t* fp;
 362   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
 363   return frame(sp, fp, epc.pc());
 364 }
 365 
 366 // VC++ does not save frame pointer on stack in optimized build. It
 367 // can be turned off by /Oy-. If we really want to walk C frames,
 368 // we can use the StackWalk() API.
 369 frame os::get_sender_for_C_frame(frame* fr) {
 370   return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
 371 }
 372 
 373 #ifndef AMD64
 374 // Returns an estimate of the current stack pointer. Result must be guaranteed
 375 // to point into the calling threads stack, and be no lower than the current
 376 // stack pointer.
 377 address os::current_stack_pointer() {
 378   int dummy;
 379   address sp = (address)&dummy;
 380   return sp;
 381 }
 382 #else
 383 // Returns the current stack pointer. Accurate value needed for
 384 // os::verify_stack_alignment().
 385 address os::current_stack_pointer() {
 386   typedef address get_sp_func();
 387   get_sp_func* func = CAST_TO_FN_PTR(get_sp_func*,
 388                                      StubRoutines::x86::get_previous_sp_entry());
 389   return (*func)();
 390 }
 391 #endif
 392 
 393 
 394 #ifndef AMD64
 395 intptr_t* _get_previous_fp() {
 396   intptr_t **frameptr;
 397   __asm {
 398     mov frameptr, ebp
 399   };
 400   return *frameptr;
 401 }
 402 #endif // !AMD64
 403 
 404 frame os::current_frame() {
 405 
 406 #ifdef AMD64
 407   // apparently _asm not supported on windows amd64
 408   typedef intptr_t*      get_fp_func           ();
 409   get_fp_func* func = CAST_TO_FN_PTR(get_fp_func*,
 410                                      StubRoutines::x86::get_previous_fp_entry());
 411   if (func == NULL) return frame(NULL, NULL, NULL);
 412   intptr_t* fp = (*func)();
 413 #else
 414   intptr_t* fp = _get_previous_fp();
 415 #endif // AMD64
 416 
 417   frame myframe((intptr_t*)os::current_stack_pointer(),
 418                 (intptr_t*)fp,
 419                 CAST_FROM_FN_PTR(address, os::current_frame));
 420   if (os::is_first_C_frame(&myframe)) {
 421     // stack is not walkable
 422     return frame(NULL, NULL, NULL);
 423   } else {
 424     return os::get_sender_for_C_frame(&myframe);
 425   }
 426 }
 427 
 428 void os::print_context(outputStream *st, void *context) {
 429   if (context == NULL) return;
 430 
 431   CONTEXT* uc = (CONTEXT*)context;
 432 
 433   st->print_cr("Registers:");
 434 #ifdef AMD64
 435   st->print(  "RAX=" INTPTR_FORMAT, uc->Rax);
 436   st->print(", RBX=" INTPTR_FORMAT, uc->Rbx);
 437   st->print(", RCX=" INTPTR_FORMAT, uc->Rcx);
 438   st->print(", RDX=" INTPTR_FORMAT, uc->Rdx);
 439   st->cr();
 440   st->print(  "RSP=" INTPTR_FORMAT, uc->Rsp);
 441   st->print(", RBP=" INTPTR_FORMAT, uc->Rbp);
 442   st->print(", RSI=" INTPTR_FORMAT, uc->Rsi);
 443   st->print(", RDI=" INTPTR_FORMAT, uc->Rdi);
 444   st->cr();
 445   st->print(  "R8 =" INTPTR_FORMAT, uc->R8);
 446   st->print(", R9 =" INTPTR_FORMAT, uc->R9);
 447   st->print(", R10=" INTPTR_FORMAT, uc->R10);
 448   st->print(", R11=" INTPTR_FORMAT, uc->R11);
 449   st->cr();
 450   st->print(  "R12=" INTPTR_FORMAT, uc->R12);
 451   st->print(", R13=" INTPTR_FORMAT, uc->R13);
 452   st->print(", R14=" INTPTR_FORMAT, uc->R14);
 453   st->print(", R15=" INTPTR_FORMAT, uc->R15);
 454   st->cr();
 455   st->print(  "RIP=" INTPTR_FORMAT, uc->Rip);
 456   st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
 457 #else
 458   st->print(  "EAX=" INTPTR_FORMAT, uc->Eax);
 459   st->print(", EBX=" INTPTR_FORMAT, uc->Ebx);
 460   st->print(", ECX=" INTPTR_FORMAT, uc->Ecx);
 461   st->print(", EDX=" INTPTR_FORMAT, uc->Edx);
 462   st->cr();
 463   st->print(  "ESP=" INTPTR_FORMAT, uc->Esp);
 464   st->print(", EBP=" INTPTR_FORMAT, uc->Ebp);
 465   st->print(", ESI=" INTPTR_FORMAT, uc->Esi);
 466   st->print(", EDI=" INTPTR_FORMAT, uc->Edi);
 467   st->cr();
 468   st->print(  "EIP=" INTPTR_FORMAT, uc->Eip);
 469   st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
 470 #endif // AMD64
 471   st->cr();
 472   st->cr();
 473 
 474   intptr_t *sp = (intptr_t *)uc->REG_SP;
 475   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
 476   print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t));
 477   st->cr();
 478 
 479   // Note: it may be unsafe to inspect memory near pc. For example, pc may
 480   // point to garbage if entry point in an nmethod is corrupted. Leave
 481   // this at the end, and hope for the best.
 482   address pc = (address)uc->REG_PC;
 483   st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
 484   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 485   st->cr();
 486 }
 487 
 488 
 489 void os::print_register_info(outputStream *st, void *context) {
 490   if (context == NULL) return;
 491 
 492   CONTEXT* uc = (CONTEXT*)context;
 493 
 494   st->print_cr("Register to memory mapping:");
 495   st->cr();
 496 
 497   // this is only for the "general purpose" registers
 498 
 499 #ifdef AMD64
 500   st->print("RAX="); print_location(st, uc->Rax);
 501   st->print("RBX="); print_location(st, uc->Rbx);
 502   st->print("RCX="); print_location(st, uc->Rcx);
 503   st->print("RDX="); print_location(st, uc->Rdx);
 504   st->print("RSP="); print_location(st, uc->Rsp);
 505   st->print("RBP="); print_location(st, uc->Rbp);
 506   st->print("RSI="); print_location(st, uc->Rsi);
 507   st->print("RDI="); print_location(st, uc->Rdi);
 508   st->print("R8 ="); print_location(st, uc->R8);
 509   st->print("R9 ="); print_location(st, uc->R9);
 510   st->print("R10="); print_location(st, uc->R10);
 511   st->print("R11="); print_location(st, uc->R11);
 512   st->print("R12="); print_location(st, uc->R12);
 513   st->print("R13="); print_location(st, uc->R13);
 514   st->print("R14="); print_location(st, uc->R14);
 515   st->print("R15="); print_location(st, uc->R15);
 516 #else
 517   st->print("EAX="); print_location(st, uc->Eax);
 518   st->print("EBX="); print_location(st, uc->Ebx);
 519   st->print("ECX="); print_location(st, uc->Ecx);
 520   st->print("EDX="); print_location(st, uc->Edx);
 521   st->print("ESP="); print_location(st, uc->Esp);
 522   st->print("EBP="); print_location(st, uc->Ebp);
 523   st->print("ESI="); print_location(st, uc->Esi);
 524   st->print("EDI="); print_location(st, uc->Edi);
 525 #endif
 526 
 527   st->cr();
 528 }
 529 
 530 extern "C" int SafeFetch32 (int * adr, int Err) {
 531    int rv = Err ;
 532    _try {
 533        rv = *((volatile int *) adr) ;
 534    } __except(EXCEPTION_EXECUTE_HANDLER) {
 535    }
 536    return rv ;
 537 }
 538 
 539 extern "C" intptr_t SafeFetchN (intptr_t * adr, intptr_t Err) {
 540    intptr_t rv = Err ;
 541    _try {
 542        rv = *((volatile intptr_t *) adr) ;
 543    } __except(EXCEPTION_EXECUTE_HANDLER) {
 544    }
 545    return rv ;
 546 }
 547 
 548 extern "C" int SpinPause () {
 549 #ifdef AMD64
 550    return 0 ;
 551 #else
 552    // pause == rep:nop
 553    // On systems that don't support pause a rep:nop
 554    // is executed as a nop.  The rep: prefix is ignored.
 555    _asm {
 556       pause ;
 557    };
 558    return 1 ;
 559 #endif // AMD64
 560 }
 561 
 562 
 563 void os::setup_fpu() {
 564 #ifndef AMD64
 565   int fpu_cntrl_word = StubRoutines::fpu_cntrl_wrd_std();
 566   __asm fldcw fpu_cntrl_word;
 567 #endif // !AMD64
 568 }
 569 
 570 #ifndef PRODUCT
 571 void os::verify_stack_alignment() {
 572 #ifdef AMD64
 573   assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
 574 #endif
 575 }
 576 #endif