os_windows_x86.cpp revision 5232:38f750491293
1/*
2 * Copyright (c) 1999, 2012, 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 "asm/macroAssembler.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 "decoder_windows.hpp"
33#include "interpreter/interpreter.hpp"
34#include "jvm_windows.h"
35#include "memory/allocation.inline.hpp"
36#include "mutex_windows.inline.hpp"
37#include "nativeInst_x86.hpp"
38#include "os_share_windows.hpp"
39#include "prims/jniFastGetField.hpp"
40#include "prims/jvm.h"
41#include "prims/jvm_misc.hpp"
42#include "runtime/arguments.hpp"
43#include "runtime/extendedPC.hpp"
44#include "runtime/frame.inline.hpp"
45#include "runtime/interfaceSupport.hpp"
46#include "runtime/java.hpp"
47#include "runtime/javaCalls.hpp"
48#include "runtime/mutexLocker.hpp"
49#include "runtime/osThread.hpp"
50#include "runtime/sharedRuntime.hpp"
51#include "runtime/stubRoutines.hpp"
52#include "runtime/thread.inline.hpp"
53#include "runtime/timer.hpp"
54#include "utilities/events.hpp"
55#include "utilities/vmError.hpp"
56
57# include "unwind_windows_x86.hpp"
58#undef REG_SP
59#undef REG_FP
60#undef REG_PC
61#ifdef AMD64
62#define REG_SP Rsp
63#define REG_FP Rbp
64#define REG_PC Rip
65#else
66#define REG_SP Esp
67#define REG_FP Ebp
68#define REG_PC Eip
69#endif // AMD64
70
71extern LONG WINAPI topLevelExceptionFilter(_EXCEPTION_POINTERS* );
72
73// Install a win32 structured exception handler around thread.
74void os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, JavaCallArguments* args, Thread* thread) {
75  __try {
76
77#ifndef AMD64
78    // We store the current thread in this wrapperthread location
79    // and determine how far away this address is from the structured
80    // execption pointer that FS:[0] points to.  This get_thread
81    // code can then get the thread pointer via FS.
82    //
83    // Warning:  This routine must NEVER be inlined since we'd end up with
84    //           multiple offsets.
85    //
86    volatile Thread* wrapperthread = thread;
87
88    if ( ThreadLocalStorage::get_thread_ptr_offset() == 0 ) {
89      int thread_ptr_offset;
90      __asm {
91        lea eax, dword ptr wrapperthread;
92        sub eax, dword ptr FS:[0H];
93        mov thread_ptr_offset, eax
94      };
95      ThreadLocalStorage::set_thread_ptr_offset(thread_ptr_offset);
96    }
97#ifdef ASSERT
98    // Verify that the offset hasn't changed since we initally captured
99    // it. This might happen if we accidentally ended up with an
100    // inlined version of this routine.
101    else {
102      int test_thread_ptr_offset;
103      __asm {
104        lea eax, dword ptr wrapperthread;
105        sub eax, dword ptr FS:[0H];
106        mov test_thread_ptr_offset, eax
107      };
108      assert(test_thread_ptr_offset == ThreadLocalStorage::get_thread_ptr_offset(),
109             "thread pointer offset from SEH changed");
110    }
111#endif // ASSERT
112#endif // !AMD64
113
114    f(value, method, args, thread);
115  } __except(topLevelExceptionFilter((_EXCEPTION_POINTERS*)_exception_info())) {
116      // Nothing to do.
117  }
118}
119
120#ifdef AMD64
121
122// This is the language specific handler for exceptions
123// originating from dynamically generated code.
124// We call the standard structured exception handler
125// We only expect Continued Execution since we cannot unwind
126// from generated code.
127LONG HandleExceptionFromCodeCache(
128  IN PEXCEPTION_RECORD ExceptionRecord,
129  IN ULONG64 EstablisherFrame,
130  IN OUT PCONTEXT ContextRecord,
131  IN OUT PDISPATCHER_CONTEXT DispatcherContext) {
132  EXCEPTION_POINTERS ep;
133  LONG result;
134
135  ep.ExceptionRecord = ExceptionRecord;
136  ep.ContextRecord = ContextRecord;
137
138  result = topLevelExceptionFilter(&ep);
139
140  // We better only get a CONTINUE_EXECUTION from our handler
141  // since we don't have unwind information registered.
142
143  guarantee( result == EXCEPTION_CONTINUE_EXECUTION,
144             "Unexpected result from topLevelExceptionFilter");
145
146  return(ExceptionContinueExecution);
147}
148
149
150// Structure containing the Windows Data Structures required
151// to register our Code Cache exception handler.
152// We put these in the CodeCache since the API requires
153// all addresses in these structures are relative to the Code
154// area registered with RtlAddFunctionTable.
155typedef struct {
156  char ExceptionHandlerInstr[16];  // jmp HandleExceptionFromCodeCache
157  RUNTIME_FUNCTION rt;
158  UNWIND_INFO_EH_ONLY unw;
159} DynamicCodeData, *pDynamicCodeData;
160
161#endif // AMD64
162//
163// Register our CodeCache area with the OS so it will dispatch exceptions
164// to our topLevelExceptionFilter when we take an exception in our
165// dynamically generated code.
166//
167// Arguments:  low and high are the address of the full reserved
168// codeCache area
169//
170bool os::register_code_area(char *low, char *high) {
171#ifdef AMD64
172
173  ResourceMark rm;
174
175  pDynamicCodeData pDCD;
176  PRUNTIME_FUNCTION prt;
177  PUNWIND_INFO_EH_ONLY punwind;
178
179  BufferBlob* blob = BufferBlob::create("CodeCache Exception Handler", sizeof(DynamicCodeData));
180  CodeBuffer cb(blob);
181  MacroAssembler* masm = new MacroAssembler(&cb);
182  pDCD = (pDynamicCodeData) masm->pc();
183
184  masm->jump(ExternalAddress((address)&HandleExceptionFromCodeCache));
185  masm->flush();
186
187  // Create an Unwind Structure specifying no unwind info
188  // other than an Exception Handler
189  punwind = &pDCD->unw;
190  punwind->Version = 1;
191  punwind->Flags = UNW_FLAG_EHANDLER;
192  punwind->SizeOfProlog = 0;
193  punwind->CountOfCodes = 0;
194  punwind->FrameRegister = 0;
195  punwind->FrameOffset = 0;
196  punwind->ExceptionHandler = (char *)(&(pDCD->ExceptionHandlerInstr[0])) -
197                              (char*)low;
198  punwind->ExceptionData[0] = 0;
199
200  // This structure describes the covered dynamic code area.
201  // Addresses are relative to the beginning on the code cache area
202  prt = &pDCD->rt;
203  prt->BeginAddress = 0;
204  prt->EndAddress = (ULONG)(high - low);
205  prt->UnwindData = ((char *)punwind - low);
206
207  guarantee(RtlAddFunctionTable(prt, 1, (ULONGLONG)low),
208            "Failed to register Dynamic Code Exception Handler with RtlAddFunctionTable");
209
210#endif // AMD64
211  return true;
212}
213
214void os::initialize_thread(Thread* thr) {
215// Nothing to do.
216}
217
218// Atomics and Stub Functions
219
220typedef jint      xchg_func_t            (jint,     volatile jint*);
221typedef intptr_t  xchg_ptr_func_t        (intptr_t, volatile intptr_t*);
222typedef jint      cmpxchg_func_t         (jint,     volatile jint*,  jint);
223typedef jlong     cmpxchg_long_func_t    (jlong,    volatile jlong*, jlong);
224typedef jint      add_func_t             (jint,     volatile jint*);
225typedef intptr_t  add_ptr_func_t         (intptr_t, volatile intptr_t*);
226
227#ifdef AMD64
228
229jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
230  // try to use the stub:
231  xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
232
233  if (func != NULL) {
234    os::atomic_xchg_func = func;
235    return (*func)(exchange_value, dest);
236  }
237  assert(Threads::number_of_threads() == 0, "for bootstrap only");
238
239  jint old_value = *dest;
240  *dest = exchange_value;
241  return old_value;
242}
243
244intptr_t os::atomic_xchg_ptr_bootstrap(intptr_t exchange_value, volatile intptr_t* dest) {
245  // try to use the stub:
246  xchg_ptr_func_t* func = CAST_TO_FN_PTR(xchg_ptr_func_t*, StubRoutines::atomic_xchg_ptr_entry());
247
248  if (func != NULL) {
249    os::atomic_xchg_ptr_func = func;
250    return (*func)(exchange_value, dest);
251  }
252  assert(Threads::number_of_threads() == 0, "for bootstrap only");
253
254  intptr_t old_value = *dest;
255  *dest = exchange_value;
256  return old_value;
257}
258
259
260jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
261  // try to use the stub:
262  cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
263
264  if (func != NULL) {
265    os::atomic_cmpxchg_func = func;
266    return (*func)(exchange_value, dest, compare_value);
267  }
268  assert(Threads::number_of_threads() == 0, "for bootstrap only");
269
270  jint old_value = *dest;
271  if (old_value == compare_value)
272    *dest = exchange_value;
273  return old_value;
274}
275#endif // AMD64
276
277jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
278  // try to use the stub:
279  cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
280
281  if (func != NULL) {
282    os::atomic_cmpxchg_long_func = func;
283    return (*func)(exchange_value, dest, compare_value);
284  }
285  assert(Threads::number_of_threads() == 0, "for bootstrap only");
286
287  jlong old_value = *dest;
288  if (old_value == compare_value)
289    *dest = exchange_value;
290  return old_value;
291}
292
293#ifdef AMD64
294
295jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
296  // try to use the stub:
297  add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
298
299  if (func != NULL) {
300    os::atomic_add_func = func;
301    return (*func)(add_value, dest);
302  }
303  assert(Threads::number_of_threads() == 0, "for bootstrap only");
304
305  return (*dest) += add_value;
306}
307
308intptr_t os::atomic_add_ptr_bootstrap(intptr_t add_value, volatile intptr_t* dest) {
309  // try to use the stub:
310  add_ptr_func_t* func = CAST_TO_FN_PTR(add_ptr_func_t*, StubRoutines::atomic_add_ptr_entry());
311
312  if (func != NULL) {
313    os::atomic_add_ptr_func = func;
314    return (*func)(add_value, dest);
315  }
316  assert(Threads::number_of_threads() == 0, "for bootstrap only");
317
318  return (*dest) += add_value;
319}
320
321xchg_func_t*         os::atomic_xchg_func         = os::atomic_xchg_bootstrap;
322xchg_ptr_func_t*     os::atomic_xchg_ptr_func     = os::atomic_xchg_ptr_bootstrap;
323cmpxchg_func_t*      os::atomic_cmpxchg_func      = os::atomic_cmpxchg_bootstrap;
324add_func_t*          os::atomic_add_func          = os::atomic_add_bootstrap;
325add_ptr_func_t*      os::atomic_add_ptr_func      = os::atomic_add_ptr_bootstrap;
326
327#endif // AMD64
328
329cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
330
331#ifdef AMD64
332/*
333 * Windows/x64 does not use stack frames the way expected by Java:
334 * [1] in most cases, there is no frame pointer. All locals are addressed via RSP
335 * [2] in rare cases, when alloca() is used, a frame pointer is used, but this may
336 *     not be RBP.
337 * See http://msdn.microsoft.com/en-us/library/ew5tede7.aspx
338 *
339 * So it's not possible to print the native stack using the
340 *     while (...) {...  fr = os::get_sender_for_C_frame(&fr); }
341 * loop in vmError.cpp. We need to roll our own loop.
342 */
343bool os::platform_print_native_stack(outputStream* st, void* context,
344                                     char *buf, int buf_size)
345{
346  CONTEXT ctx;
347  if (context != NULL) {
348    memcpy(&ctx, context, sizeof(ctx));
349  } else {
350    RtlCaptureContext(&ctx);
351  }
352
353  st->print_cr("Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)");
354
355  STACKFRAME stk;
356  memset(&stk, 0, sizeof(stk));
357  stk.AddrStack.Offset    = ctx.Rsp;
358  stk.AddrStack.Mode      = AddrModeFlat;
359  stk.AddrFrame.Offset    = ctx.Rbp;
360  stk.AddrFrame.Mode      = AddrModeFlat;
361  stk.AddrPC.Offset       = ctx.Rip;
362  stk.AddrPC.Mode         = AddrModeFlat;
363
364  int count = 0;
365  address lastpc = 0;
366  while (count++ < StackPrintLimit) {
367    intptr_t* sp = (intptr_t*)stk.AddrStack.Offset;
368    intptr_t* fp = (intptr_t*)stk.AddrFrame.Offset; // NOT necessarily the same as ctx.Rbp!
369    address pc = (address)stk.AddrPC.Offset;
370
371    if (pc != NULL && sp != NULL && fp != NULL) {
372      if (count == 2 && lastpc == pc) {
373        // Skip it -- StackWalk64() may return the same PC
374        // (but different SP) on the first try.
375      } else {
376        // Don't try to create a frame(sp, fp, pc) -- on WinX64, stk.AddrFrame
377        // may not contain what Java expects, and may cause the frame() constructor
378        // to crash. Let's just print out the symbolic address.
379        frame::print_C_frame(st, buf, buf_size, pc);
380        st->cr();
381      }
382      lastpc = pc;
383    } else {
384      break;
385    }
386
387    PVOID p = WindowsDbgHelp::SymFunctionTableAccess64(GetCurrentProcess(), stk.AddrPC.Offset);
388    if (!p) {
389      // StackWalk64() can't handle this PC. Calling StackWalk64 again may cause crash.
390      break;
391    }
392
393    BOOL result = WindowsDbgHelp::StackWalk64(
394        IMAGE_FILE_MACHINE_AMD64,  // __in      DWORD MachineType,
395        GetCurrentProcess(),       // __in      HANDLE hProcess,
396        GetCurrentThread(),        // __in      HANDLE hThread,
397        &stk,                      // __inout   LP STACKFRAME64 StackFrame,
398        &ctx,                      // __inout   PVOID ContextRecord,
399        NULL,                      // __in_opt  PREAD_PROCESS_MEMORY_ROUTINE64 ReadMemoryRoutine,
400        WindowsDbgHelp::pfnSymFunctionTableAccess64(),
401                                   // __in_opt  PFUNCTION_TABLE_ACCESS_ROUTINE64 FunctionTableAccessRoutine,
402        WindowsDbgHelp::pfnSymGetModuleBase64(),
403                                   // __in_opt  PGET_MODULE_BASE_ROUTINE64 GetModuleBaseRoutine,
404        NULL);                     // __in_opt  PTRANSLATE_ADDRESS_ROUTINE64 TranslateAddress
405
406    if (!result) {
407      break;
408    }
409  }
410  if (count > StackPrintLimit) {
411    st->print_cr("...<more frames>...");
412  }
413  st->cr();
414
415  return true;
416}
417#endif // AMD64
418
419ExtendedPC os::fetch_frame_from_context(void* ucVoid,
420                    intptr_t** ret_sp, intptr_t** ret_fp) {
421
422  ExtendedPC  epc;
423  CONTEXT* uc = (CONTEXT*)ucVoid;
424
425  if (uc != NULL) {
426    epc = ExtendedPC((address)uc->REG_PC);
427    if (ret_sp) *ret_sp = (intptr_t*)uc->REG_SP;
428    if (ret_fp) *ret_fp = (intptr_t*)uc->REG_FP;
429  } else {
430    // construct empty ExtendedPC for return value checking
431    epc = ExtendedPC(NULL);
432    if (ret_sp) *ret_sp = (intptr_t *)NULL;
433    if (ret_fp) *ret_fp = (intptr_t *)NULL;
434  }
435
436  return epc;
437}
438
439frame os::fetch_frame_from_context(void* ucVoid) {
440  intptr_t* sp;
441  intptr_t* fp;
442  ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
443  return frame(sp, fp, epc.pc());
444}
445
446// VC++ does not save frame pointer on stack in optimized build. It
447// can be turned off by /Oy-. If we really want to walk C frames,
448// we can use the StackWalk() API.
449frame os::get_sender_for_C_frame(frame* fr) {
450  return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
451}
452
453#ifndef AMD64
454// Returns an estimate of the current stack pointer. Result must be guaranteed
455// to point into the calling threads stack, and be no lower than the current
456// stack pointer.
457address os::current_stack_pointer() {
458  int dummy;
459  address sp = (address)&dummy;
460  return sp;
461}
462#else
463// Returns the current stack pointer. Accurate value needed for
464// os::verify_stack_alignment().
465address os::current_stack_pointer() {
466  typedef address get_sp_func();
467  get_sp_func* func = CAST_TO_FN_PTR(get_sp_func*,
468                                     StubRoutines::x86::get_previous_sp_entry());
469  return (*func)();
470}
471#endif
472
473
474#ifndef AMD64
475intptr_t* _get_previous_fp() {
476  intptr_t **frameptr;
477  __asm {
478    mov frameptr, ebp
479  };
480  return *frameptr;
481}
482#endif // !AMD64
483
484frame os::current_frame() {
485
486#ifdef AMD64
487  // apparently _asm not supported on windows amd64
488  typedef intptr_t*      get_fp_func           ();
489  get_fp_func* func = CAST_TO_FN_PTR(get_fp_func*,
490                                     StubRoutines::x86::get_previous_fp_entry());
491  if (func == NULL) return frame();
492  intptr_t* fp = (*func)();
493  if (fp == NULL) {
494    return frame();
495  }
496#else
497  intptr_t* fp = _get_previous_fp();
498#endif // AMD64
499
500  frame myframe((intptr_t*)os::current_stack_pointer(),
501                (intptr_t*)fp,
502                CAST_FROM_FN_PTR(address, os::current_frame));
503  if (os::is_first_C_frame(&myframe)) {
504    // stack is not walkable
505    return frame();
506  } else {
507    return os::get_sender_for_C_frame(&myframe);
508  }
509}
510
511void os::print_context(outputStream *st, void *context) {
512  if (context == NULL) return;
513
514  CONTEXT* uc = (CONTEXT*)context;
515
516  st->print_cr("Registers:");
517#ifdef AMD64
518  st->print(  "RAX=" INTPTR_FORMAT, uc->Rax);
519  st->print(", RBX=" INTPTR_FORMAT, uc->Rbx);
520  st->print(", RCX=" INTPTR_FORMAT, uc->Rcx);
521  st->print(", RDX=" INTPTR_FORMAT, uc->Rdx);
522  st->cr();
523  st->print(  "RSP=" INTPTR_FORMAT, uc->Rsp);
524  st->print(", RBP=" INTPTR_FORMAT, uc->Rbp);
525  st->print(", RSI=" INTPTR_FORMAT, uc->Rsi);
526  st->print(", RDI=" INTPTR_FORMAT, uc->Rdi);
527  st->cr();
528  st->print(  "R8 =" INTPTR_FORMAT, uc->R8);
529  st->print(", R9 =" INTPTR_FORMAT, uc->R9);
530  st->print(", R10=" INTPTR_FORMAT, uc->R10);
531  st->print(", R11=" INTPTR_FORMAT, uc->R11);
532  st->cr();
533  st->print(  "R12=" INTPTR_FORMAT, uc->R12);
534  st->print(", R13=" INTPTR_FORMAT, uc->R13);
535  st->print(", R14=" INTPTR_FORMAT, uc->R14);
536  st->print(", R15=" INTPTR_FORMAT, uc->R15);
537  st->cr();
538  st->print(  "RIP=" INTPTR_FORMAT, uc->Rip);
539  st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
540#else
541  st->print(  "EAX=" INTPTR_FORMAT, uc->Eax);
542  st->print(", EBX=" INTPTR_FORMAT, uc->Ebx);
543  st->print(", ECX=" INTPTR_FORMAT, uc->Ecx);
544  st->print(", EDX=" INTPTR_FORMAT, uc->Edx);
545  st->cr();
546  st->print(  "ESP=" INTPTR_FORMAT, uc->Esp);
547  st->print(", EBP=" INTPTR_FORMAT, uc->Ebp);
548  st->print(", ESI=" INTPTR_FORMAT, uc->Esi);
549  st->print(", EDI=" INTPTR_FORMAT, uc->Edi);
550  st->cr();
551  st->print(  "EIP=" INTPTR_FORMAT, uc->Eip);
552  st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
553#endif // AMD64
554  st->cr();
555  st->cr();
556
557  intptr_t *sp = (intptr_t *)uc->REG_SP;
558  st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
559  print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t));
560  st->cr();
561
562  // Note: it may be unsafe to inspect memory near pc. For example, pc may
563  // point to garbage if entry point in an nmethod is corrupted. Leave
564  // this at the end, and hope for the best.
565  address pc = (address)uc->REG_PC;
566  st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
567  print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
568  st->cr();
569}
570
571
572void os::print_register_info(outputStream *st, void *context) {
573  if (context == NULL) return;
574
575  CONTEXT* uc = (CONTEXT*)context;
576
577  st->print_cr("Register to memory mapping:");
578  st->cr();
579
580  // this is only for the "general purpose" registers
581
582#ifdef AMD64
583  st->print("RAX="); print_location(st, uc->Rax);
584  st->print("RBX="); print_location(st, uc->Rbx);
585  st->print("RCX="); print_location(st, uc->Rcx);
586  st->print("RDX="); print_location(st, uc->Rdx);
587  st->print("RSP="); print_location(st, uc->Rsp);
588  st->print("RBP="); print_location(st, uc->Rbp);
589  st->print("RSI="); print_location(st, uc->Rsi);
590  st->print("RDI="); print_location(st, uc->Rdi);
591  st->print("R8 ="); print_location(st, uc->R8);
592  st->print("R9 ="); print_location(st, uc->R9);
593  st->print("R10="); print_location(st, uc->R10);
594  st->print("R11="); print_location(st, uc->R11);
595  st->print("R12="); print_location(st, uc->R12);
596  st->print("R13="); print_location(st, uc->R13);
597  st->print("R14="); print_location(st, uc->R14);
598  st->print("R15="); print_location(st, uc->R15);
599#else
600  st->print("EAX="); print_location(st, uc->Eax);
601  st->print("EBX="); print_location(st, uc->Ebx);
602  st->print("ECX="); print_location(st, uc->Ecx);
603  st->print("EDX="); print_location(st, uc->Edx);
604  st->print("ESP="); print_location(st, uc->Esp);
605  st->print("EBP="); print_location(st, uc->Ebp);
606  st->print("ESI="); print_location(st, uc->Esi);
607  st->print("EDI="); print_location(st, uc->Edi);
608#endif
609
610  st->cr();
611}
612
613extern "C" int SpinPause () {
614#ifdef AMD64
615   return 0 ;
616#else
617   // pause == rep:nop
618   // On systems that don't support pause a rep:nop
619   // is executed as a nop.  The rep: prefix is ignored.
620   _asm {
621      pause ;
622   };
623   return 1 ;
624#endif // AMD64
625}
626
627
628void os::setup_fpu() {
629#ifndef AMD64
630  int fpu_cntrl_word = StubRoutines::fpu_cntrl_wrd_std();
631  __asm fldcw fpu_cntrl_word;
632#endif // !AMD64
633}
634
635#ifndef PRODUCT
636void os::verify_stack_alignment() {
637#ifdef AMD64
638  assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
639#endif
640}
641#endif
642