1 /*
   2  * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/systemDictionary.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "code/debugInfoRec.hpp"
  29 #include "code/nmethod.hpp"
  30 #include "code/pcDesc.hpp"
  31 #include "code/scopeDesc.hpp"
  32 #include "interpreter/bytecode.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "interpreter/oopMapCache.hpp"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/oopFactory.hpp"
  37 #include "memory/resourceArea.hpp"
  38 #include "oops/method.hpp"
  39 #include "oops/objArrayOop.inline.hpp"
  40 #include "oops/oop.inline.hpp"
  41 #include "oops/fieldStreams.hpp"
  42 #include "oops/valueKlass.hpp"
  43 #include "oops/verifyOopClosure.hpp"
  44 #include "prims/jvmtiThreadState.hpp"
  45 #include "runtime/biasedLocking.hpp"
  46 #include "runtime/compilationPolicy.hpp"
  47 #include "runtime/deoptimization.hpp"
  48 #include "runtime/interfaceSupport.hpp"
  49 #include "runtime/sharedRuntime.hpp"
  50 #include "runtime/signature.hpp"
  51 #include "runtime/stubRoutines.hpp"
  52 #include "runtime/thread.hpp"
  53 #include "runtime/vframe.hpp"
  54 #include "runtime/vframeArray.hpp"
  55 #include "runtime/vframe_hp.hpp"
  56 #include "utilities/events.hpp"
  57 #include "utilities/xmlstream.hpp"
  58 
  59 #if INCLUDE_JVMCI
  60 #include "jvmci/jvmciRuntime.hpp"
  61 #include "jvmci/jvmciJavaClasses.hpp"
  62 #endif
  63 
  64 
  65 bool DeoptimizationMarker::_is_active = false;
  66 
  67 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
  68                                          int  caller_adjustment,
  69                                          int  caller_actual_parameters,
  70                                          int  number_of_frames,
  71                                          intptr_t* frame_sizes,
  72                                          address* frame_pcs,
  73                                          BasicType return_type,
  74                                          int exec_mode) {
  75   _size_of_deoptimized_frame = size_of_deoptimized_frame;
  76   _caller_adjustment         = caller_adjustment;
  77   _caller_actual_parameters  = caller_actual_parameters;
  78   _number_of_frames          = number_of_frames;
  79   _frame_sizes               = frame_sizes;
  80   _frame_pcs                 = frame_pcs;
  81   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
  82   _return_type               = return_type;
  83   _initial_info              = 0;
  84   // PD (x86 only)
  85   _counter_temp              = 0;
  86   _unpack_kind               = exec_mode;
  87   _sender_sp_temp            = 0;
  88 
  89   _total_frame_sizes         = size_of_frames();
  90   assert(exec_mode >= 0 && exec_mode < Unpack_LIMIT, "Unexpected exec_mode");
  91 }
  92 
  93 
  94 Deoptimization::UnrollBlock::~UnrollBlock() {
  95   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
  96   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
  97   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
  98 }
  99 
 100 
 101 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
 102   assert(register_number < RegisterMap::reg_count, "checking register number");
 103   return &_register_block[register_number * 2];
 104 }
 105 
 106 
 107 
 108 int Deoptimization::UnrollBlock::size_of_frames() const {
 109   // Acount first for the adjustment of the initial frame
 110   int result = _caller_adjustment;
 111   for (int index = 0; index < number_of_frames(); index++) {
 112     result += frame_sizes()[index];
 113   }
 114   return result;
 115 }
 116 
 117 
 118 void Deoptimization::UnrollBlock::print() {
 119   ttyLocker ttyl;
 120   tty->print_cr("UnrollBlock");
 121   tty->print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 122   tty->print(   "  frame_sizes: ");
 123   for (int index = 0; index < number_of_frames(); index++) {
 124     tty->print(INTX_FORMAT " ", frame_sizes()[index]);
 125   }
 126   tty->cr();
 127 }
 128 
 129 
 130 // In order to make fetch_unroll_info work properly with escape
 131 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
 132 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
 133 // of previously eliminated objects occurs in realloc_objects, which is
 134 // called from the method fetch_unroll_info_helper below.
 135 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread, int exec_mode))
 136   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 137   // but makes the entry a little slower. There is however a little dance we have to
 138   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 139 
 140   // fetch_unroll_info() is called at the beginning of the deoptimization
 141   // handler. Note this fact before we start generating temporary frames
 142   // that can confuse an asynchronous stack walker. This counter is
 143   // decremented at the end of unpack_frames().
 144   if (TraceDeoptimization) {
 145     tty->print_cr("Deoptimizing thread " INTPTR_FORMAT, p2i(thread));
 146   }
 147   thread->inc_in_deopt_handler();
 148 
 149   return fetch_unroll_info_helper(thread, exec_mode);
 150 JRT_END
 151 
 152 
 153 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 154 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread, int exec_mode) {
 155 
 156   // Note: there is a safepoint safety issue here. No matter whether we enter
 157   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 158   // the vframeArray is created.
 159   //
 160 
 161   // Allocate our special deoptimization ResourceMark
 162   DeoptResourceMark* dmark = new DeoptResourceMark(thread);
 163   assert(thread->deopt_mark() == NULL, "Pending deopt!");
 164   thread->set_deopt_mark(dmark);
 165 
 166   frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
 167   RegisterMap map(thread, true);
 168   RegisterMap dummy_map(thread, false);
 169   // Now get the deoptee with a valid map
 170   frame deoptee = stub_frame.sender(&map);
 171   // Set the deoptee nmethod
 172   assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
 173   thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
 174   bool skip_internal = thread->deopt_nmethod() != NULL && !thread->deopt_nmethod()->compiler()->is_jvmci();
 175 
 176   if (VerifyStack) {
 177     thread->validate_frame_layout();
 178   }
 179 
 180   // Create a growable array of VFrames where each VFrame represents an inlined
 181   // Java frame.  This storage is allocated with the usual system arena.
 182   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 183   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 184   vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
 185   while (!vf->is_top()) {
 186     assert(vf->is_compiled_frame(), "Wrong frame type");
 187     chunk->push(compiledVFrame::cast(vf));
 188     vf = vf->sender();
 189   }
 190   assert(vf->is_compiled_frame(), "Wrong frame type");
 191   chunk->push(compiledVFrame::cast(vf));
 192 
 193   ScopeDesc* trap_scope = chunk->at(0)->scope();
 194   Handle exceptionObject;
 195   if (trap_scope->rethrow_exception()) {
 196     if (PrintDeoptimizationDetails) {
 197       tty->print_cr("Exception to be rethrown in the interpreter for method %s::%s at bci %d", trap_scope->method()->method_holder()->name()->as_C_string(), trap_scope->method()->name()->as_C_string(), trap_scope->bci());
 198     }
 199     GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
 200     guarantee(expressions != NULL && expressions->length() > 0, "must have exception to throw");
 201     ScopeValue* topOfStack = expressions->top();
 202     exceptionObject = StackValue::create_stack_value(&deoptee, &map, topOfStack)->get_obj();
 203     assert(exceptionObject() != NULL, "exception oop can not be null");
 204   }
 205 
 206   bool realloc_failures = false;
 207 
 208 #if defined(COMPILER2) || INCLUDE_JVMCI
 209   // Reallocate the non-escaping objects and restore their fields. Then
 210   // relock objects if synchronization on them was eliminated.
 211 #ifndef INCLUDE_JVMCI
 212   if (DoEscapeAnalysis || EliminateNestedLocks) {
 213     if (EliminateAllocations) {
 214 #endif // INCLUDE_JVMCI
 215       assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
 216       GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
 217 
 218       // The flag return_oop() indicates call sites which return oop
 219       // in compiled code. Such sites include java method calls,
 220       // runtime calls (for example, used to allocate new objects/arrays
 221       // on slow code path) and any other calls generated in compiled code.
 222       // It is not guaranteed that we can get such information here only
 223       // by analyzing bytecode in deoptimized frames. This is why this flag
 224       // is set during method compilation (see Compile::Process_OopMap_Node()).
 225       // If the previous frame was popped, we don't have a result.
 226       bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution();
 227       Handle return_value;
 228       if (save_oop_result) {
 229         // Reallocation may trigger GC. If deoptimization happened on return from
 230         // call which returns oop we need to save it since it is not in oopmap.
 231         oop result = deoptee.saved_oop_result(&map);
 232         assert(result == NULL || result->is_oop(), "must be oop");
 233         return_value = Handle(thread, result);
 234         assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 235         if (TraceDeoptimization) {
 236           ttyLocker ttyl;
 237           tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
 238         }
 239       }
 240       if (objects != NULL) {
 241         JRT_BLOCK
 242           realloc_failures = realloc_objects(thread, &deoptee, objects, THREAD);
 243           reassign_fields(&deoptee, &map, objects, realloc_failures, skip_internal, THREAD);
 244         JRT_END
 245 #ifndef PRODUCT
 246         if (TraceDeoptimization) {
 247           ttyLocker ttyl;
 248           tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
 249           print_objects(objects, realloc_failures);
 250         }
 251 #endif
 252       }
 253       if (save_oop_result) {
 254         // Restore result.
 255         deoptee.set_saved_oop_result(&map, return_value());
 256       }
 257 #ifndef INCLUDE_JVMCI
 258     }
 259     if (EliminateLocks) {
 260 #endif // INCLUDE_JVMCI
 261 #ifndef PRODUCT
 262       bool first = true;
 263 #endif
 264       for (int i = 0; i < chunk->length(); i++) {
 265         compiledVFrame* cvf = chunk->at(i);
 266         assert (cvf->scope() != NULL,"expect only compiled java frames");
 267         GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 268         if (monitors->is_nonempty()) {
 269           relock_objects(monitors, thread, realloc_failures);
 270 #ifndef PRODUCT
 271           if (PrintDeoptimizationDetails) {
 272             ttyLocker ttyl;
 273             for (int j = 0; j < monitors->length(); j++) {
 274               MonitorInfo* mi = monitors->at(j);
 275               if (mi->eliminated()) {
 276                 if (first) {
 277                   first = false;
 278                   tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
 279                 }
 280                 if (mi->owner_is_scalar_replaced()) {
 281                   Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
 282                   tty->print_cr("     failed reallocation for klass %s", k->external_name());
 283                 } else {
 284                   tty->print_cr("     object <" INTPTR_FORMAT "> locked", p2i(mi->owner()));
 285                 }
 286               }
 287             }
 288           }
 289 #endif // !PRODUCT
 290         }
 291       }
 292 #ifndef INCLUDE_JVMCI
 293     }
 294   }
 295 #endif // INCLUDE_JVMCI
 296 #endif // COMPILER2 || INCLUDE_JVMCI
 297 
 298   // Ensure that no safepoint is taken after pointers have been stored
 299   // in fields of rematerialized objects.  If a safepoint occurs from here on
 300   // out the java state residing in the vframeArray will be missed.
 301   NoSafepointVerifier no_safepoint;
 302 
 303   vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk, realloc_failures);
 304 #if defined(COMPILER2) || INCLUDE_JVMCI
 305   if (realloc_failures) {
 306     pop_frames_failed_reallocs(thread, array);
 307   }
 308 #endif
 309 
 310   assert(thread->vframe_array_head() == NULL, "Pending deopt!");
 311   thread->set_vframe_array_head(array);
 312 
 313   // Now that the vframeArray has been created if we have any deferred local writes
 314   // added by jvmti then we can free up that structure as the data is now in the
 315   // vframeArray
 316 
 317   if (thread->deferred_locals() != NULL) {
 318     GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
 319     int i = 0;
 320     do {
 321       // Because of inlining we could have multiple vframes for a single frame
 322       // and several of the vframes could have deferred writes. Find them all.
 323       if (list->at(i)->id() == array->original().id()) {
 324         jvmtiDeferredLocalVariableSet* dlv = list->at(i);
 325         list->remove_at(i);
 326         // individual jvmtiDeferredLocalVariableSet are CHeapObj's
 327         delete dlv;
 328       } else {
 329         i++;
 330       }
 331     } while ( i < list->length() );
 332     if (list->length() == 0) {
 333       thread->set_deferred_locals(NULL);
 334       // free the list and elements back to C heap.
 335       delete list;
 336     }
 337 
 338   }
 339 
 340 #ifndef SHARK
 341   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 342   CodeBlob* cb = stub_frame.cb();
 343   // Verify we have the right vframeArray
 344   assert(cb->frame_size() >= 0, "Unexpected frame size");
 345   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 346 
 347   // If the deopt call site is a MethodHandle invoke call site we have
 348   // to adjust the unpack_sp.
 349   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
 350   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
 351     unpack_sp = deoptee.unextended_sp();
 352 
 353 #ifdef ASSERT
 354   assert(cb->is_deoptimization_stub() ||
 355          cb->is_uncommon_trap_stub() ||
 356          strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
 357          strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
 358          "unexpected code blob: %s", cb->name());
 359 #endif
 360 #else
 361   intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
 362 #endif // !SHARK
 363 
 364   // This is a guarantee instead of an assert because if vframe doesn't match
 365   // we will unpack the wrong deoptimized frame and wind up in strange places
 366   // where it will be very difficult to figure out what went wrong. Better
 367   // to die an early death here than some very obscure death later when the
 368   // trail is cold.
 369   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
 370   // in that it will fail to detect a problem when there is one. This needs
 371   // more work in tiger timeframe.
 372   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 373 
 374   int number_of_frames = array->frames();
 375 
 376   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 377   // virtual activation, which is the reverse of the elements in the vframes array.
 378   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
 379   // +1 because we always have an interpreter return address for the final slot.
 380   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
 381   int popframe_extra_args = 0;
 382   // Create an interpreter return address for the stub to use as its return
 383   // address so the skeletal frames are perfectly walkable
 384   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 385 
 386   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 387   // activation be put back on the expression stack of the caller for reexecution
 388   if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
 389     popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
 390   }
 391 
 392   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 393   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 394   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 395   //
 396   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 397   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 398 
 399   // It's possible that the number of parameters at the call site is
 400   // different than number of arguments in the callee when method
 401   // handles are used.  If the caller is interpreted get the real
 402   // value so that the proper amount of space can be added to it's
 403   // frame.
 404   bool caller_was_method_handle = false;
 405   if (deopt_sender.is_interpreted_frame()) {
 406     methodHandle method = deopt_sender.interpreter_frame_method();
 407     Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
 408     if (cur.is_invokedynamic() || cur.is_invokehandle()) {
 409       // Method handle invokes may involve fairly arbitrary chains of
 410       // calls so it's impossible to know how much actual space the
 411       // caller has for locals.
 412       caller_was_method_handle = true;
 413     }
 414   }
 415 
 416   //
 417   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 418   // frame_sizes/frame_pcs[1] next oldest frame (int)
 419   // frame_sizes/frame_pcs[n] youngest frame (int)
 420   //
 421   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 422   // owns the space for the return address to it's caller).  Confusing ain't it.
 423   //
 424   // The vframe array can address vframes with indices running from
 425   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 426   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 427   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 428   // so things look a little strange in this loop.
 429   //
 430   int callee_parameters = 0;
 431   int callee_locals = 0;
 432   for (int index = 0; index < array->frames(); index++ ) {
 433     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 434     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 435     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 436     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
 437                                                                                                     callee_locals,
 438                                                                                                     index == 0,
 439                                                                                                     popframe_extra_args);
 440     // This pc doesn't have to be perfect just good enough to identify the frame
 441     // as interpreted so the skeleton frame will be walkable
 442     // The correct pc will be set when the skeleton frame is completely filled out
 443     // The final pc we store in the loop is wrong and will be overwritten below
 444     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 445 
 446     callee_parameters = array->element(index)->method()->size_of_parameters();
 447     callee_locals = array->element(index)->method()->max_locals();
 448     popframe_extra_args = 0;
 449   }
 450 
 451   // Compute whether the root vframe returns a float or double value.
 452   BasicType return_type;
 453   {
 454     HandleMark hm;
 455     methodHandle method(thread, array->element(0)->method());
 456     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 457     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 458   }
 459 
 460   // Compute information for handling adapters and adjusting the frame size of the caller.
 461   int caller_adjustment = 0;
 462 
 463   // Compute the amount the oldest interpreter frame will have to adjust
 464   // its caller's stack by. If the caller is a compiled frame then
 465   // we pretend that the callee has no parameters so that the
 466   // extension counts for the full amount of locals and not just
 467   // locals-parms. This is because without a c2i adapter the parm
 468   // area as created by the compiled frame will not be usable by
 469   // the interpreter. (Depending on the calling convention there
 470   // may not even be enough space).
 471 
 472   // QQQ I'd rather see this pushed down into last_frame_adjust
 473   // and have it take the sender (aka caller).
 474 
 475   if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
 476     caller_adjustment = last_frame_adjust(0, callee_locals);
 477   } else if (callee_locals > callee_parameters) {
 478     // The caller frame may need extending to accommodate
 479     // non-parameter locals of the first unpacked interpreted frame.
 480     // Compute that adjustment.
 481     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 482   }
 483 
 484   // If the sender is deoptimized the we must retrieve the address of the handler
 485   // since the frame will "magically" show the original pc before the deopt
 486   // and we'd undo the deopt.
 487 
 488   frame_pcs[0] = deopt_sender.raw_pc();
 489 
 490 #ifndef SHARK
 491   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
 492 #endif // SHARK
 493 
 494 #ifdef INCLUDE_JVMCI
 495   if (exceptionObject() != NULL) {
 496     thread->set_exception_oop(exceptionObject());
 497     exec_mode = Unpack_exception;
 498   }
 499 #endif
 500 
 501   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 502                                       caller_adjustment * BytesPerWord,
 503                                       caller_was_method_handle ? 0 : callee_parameters,
 504                                       number_of_frames,
 505                                       frame_sizes,
 506                                       frame_pcs,
 507                                       return_type,
 508                                       exec_mode);
 509   // On some platforms, we need a way to pass some platform dependent
 510   // information to the unpacking code so the skeletal frames come out
 511   // correct (initial fp value, unextended sp, ...)
 512   info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
 513 
 514   if (array->frames() > 1) {
 515     if (VerifyStack && TraceDeoptimization) {
 516       ttyLocker ttyl;
 517       tty->print_cr("Deoptimizing method containing inlining");
 518     }
 519   }
 520 
 521   array->set_unroll_block(info);
 522   return info;
 523 }
 524 
 525 // Called to cleanup deoptimization data structures in normal case
 526 // after unpacking to stack and when stack overflow error occurs
 527 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 528                                         vframeArray *array) {
 529 
 530   // Get array if coming from exception
 531   if (array == NULL) {
 532     array = thread->vframe_array_head();
 533   }
 534   thread->set_vframe_array_head(NULL);
 535 
 536   // Free the previous UnrollBlock
 537   vframeArray* old_array = thread->vframe_array_last();
 538   thread->set_vframe_array_last(array);
 539 
 540   if (old_array != NULL) {
 541     UnrollBlock* old_info = old_array->unroll_block();
 542     old_array->set_unroll_block(NULL);
 543     delete old_info;
 544     delete old_array;
 545   }
 546 
 547   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 548   // inside the vframeArray (StackValueCollections)
 549 
 550   delete thread->deopt_mark();
 551   thread->set_deopt_mark(NULL);
 552   thread->set_deopt_nmethod(NULL);
 553 
 554 
 555   if (JvmtiExport::can_pop_frame()) {
 556 #ifndef CC_INTERP
 557     // Regardless of whether we entered this routine with the pending
 558     // popframe condition bit set, we should always clear it now
 559     thread->clear_popframe_condition();
 560 #else
 561     // C++ interpreter will clear has_pending_popframe when it enters
 562     // with method_resume. For deopt_resume2 we clear it now.
 563     if (thread->popframe_forcing_deopt_reexecution())
 564         thread->clear_popframe_condition();
 565 #endif /* CC_INTERP */
 566   }
 567 
 568   // unpack_frames() is called at the end of the deoptimization handler
 569   // and (in C2) at the end of the uncommon trap handler. Note this fact
 570   // so that an asynchronous stack walker can work again. This counter is
 571   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 572   // the beginning of uncommon_trap().
 573   thread->dec_in_deopt_handler();
 574 }
 575 
 576 // Moved from cpu directories because none of the cpus has callee save values.
 577 // If a cpu implements callee save values, move this to deoptimization_<cpu>.cpp.
 578 void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
 579 
 580   // This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
 581   // the days we had adapter frames. When we deoptimize a situation where a
 582   // compiled caller calls a compiled caller will have registers it expects
 583   // to survive the call to the callee. If we deoptimize the callee the only
 584   // way we can restore these registers is to have the oldest interpreter
 585   // frame that we create restore these values. That is what this routine
 586   // will accomplish.
 587 
 588   // At the moment we have modified c2 to not have any callee save registers
 589   // so this problem does not exist and this routine is just a place holder.
 590 
 591   assert(f->is_interpreted_frame(), "must be interpreted");
 592 }
 593 
 594 // Return BasicType of value being returned
 595 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 596 
 597   // We are already active int he special DeoptResourceMark any ResourceObj's we
 598   // allocate will be freed at the end of the routine.
 599 
 600   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 601   // but makes the entry a little slower. There is however a little dance we have to
 602   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 603   ResetNoHandleMark rnhm; // No-op in release/product versions
 604   HandleMark hm;
 605 
 606   frame stub_frame = thread->last_frame();
 607 
 608   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 609   // must point to the vframeArray for the unpack frame.
 610   vframeArray* array = thread->vframe_array_head();
 611 
 612 #ifndef PRODUCT
 613   if (TraceDeoptimization) {
 614     ttyLocker ttyl;
 615     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d",
 616                   p2i(thread), p2i(array), exec_mode);
 617   }
 618 #endif
 619   Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
 620               p2i(stub_frame.pc()), p2i(stub_frame.sp()), exec_mode);
 621 
 622   UnrollBlock* info = array->unroll_block();
 623 
 624   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 625   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
 626 
 627   BasicType bt = info->return_type();
 628 
 629   // If we have an exception pending, claim that the return type is an oop
 630   // so the deopt_blob does not overwrite the exception_oop.
 631 
 632   if (exec_mode == Unpack_exception)
 633     bt = T_OBJECT;
 634 
 635   // Cleanup thread deopt data
 636   cleanup_deopt_info(thread, array);
 637 
 638 #ifndef PRODUCT
 639   if (VerifyStack) {
 640     ResourceMark res_mark;
 641 
 642     thread->validate_frame_layout();
 643 
 644     // Verify that the just-unpacked frames match the interpreter's
 645     // notions of expression stack and locals
 646     vframeArray* cur_array = thread->vframe_array_last();
 647     RegisterMap rm(thread, false);
 648     rm.set_include_argument_oops(false);
 649     bool is_top_frame = true;
 650     int callee_size_of_parameters = 0;
 651     int callee_max_locals = 0;
 652     for (int i = 0; i < cur_array->frames(); i++) {
 653       vframeArrayElement* el = cur_array->element(i);
 654       frame* iframe = el->iframe();
 655       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 656 
 657       // Get the oop map for this bci
 658       InterpreterOopMap mask;
 659       int cur_invoke_parameter_size = 0;
 660       bool try_next_mask = false;
 661       int next_mask_expression_stack_size = -1;
 662       int top_frame_expression_stack_adjustment = 0;
 663       methodHandle mh(thread, iframe->interpreter_frame_method());
 664       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
 665       BytecodeStream str(mh);
 666       str.set_start(iframe->interpreter_frame_bci());
 667       int max_bci = mh->code_size();
 668       // Get to the next bytecode if possible
 669       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 670       // Check to see if we can grab the number of outgoing arguments
 671       // at an uncommon trap for an invoke (where the compiler
 672       // generates debug info before the invoke has executed)
 673       Bytecodes::Code cur_code = str.next();
 674       if (cur_code == Bytecodes::_invokevirtual   ||
 675           cur_code == Bytecodes::_invokedirect    ||
 676           cur_code == Bytecodes::_invokespecial   ||
 677           cur_code == Bytecodes::_invokestatic    ||
 678           cur_code == Bytecodes::_invokeinterface ||
 679           cur_code == Bytecodes::_invokedynamic) {
 680         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
 681         Symbol* signature = invoke.signature();
 682         ArgumentSizeComputer asc(signature);
 683         cur_invoke_parameter_size = asc.size();
 684         if (invoke.has_receiver()) {
 685           // Add in receiver
 686           ++cur_invoke_parameter_size;
 687         }
 688         if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
 689           callee_size_of_parameters++;
 690         }
 691       }
 692       if (str.bci() < max_bci) {
 693         Bytecodes::Code bc = str.next();
 694         if (bc >= 0) {
 695           // The interpreter oop map generator reports results before
 696           // the current bytecode has executed except in the case of
 697           // calls. It seems to be hard to tell whether the compiler
 698           // has emitted debug information matching the "state before"
 699           // a given bytecode or the state after, so we try both
 700           switch (cur_code) {
 701             case Bytecodes::_invokevirtual:
 702             case Bytecodes::_invokedirect:
 703             case Bytecodes::_invokespecial:
 704             case Bytecodes::_invokestatic:
 705             case Bytecodes::_invokeinterface:
 706             case Bytecodes::_invokedynamic:
 707             case Bytecodes::_athrow:
 708               break;
 709             default: {
 710               InterpreterOopMap next_mask;
 711               OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
 712               next_mask_expression_stack_size = next_mask.expression_stack_size();
 713               // Need to subtract off the size of the result type of
 714               // the bytecode because this is not described in the
 715               // debug info but returned to the interpreter in the TOS
 716               // caching register
 717               BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 718               if (bytecode_result_type != T_ILLEGAL) {
 719                 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 720               }
 721               assert(top_frame_expression_stack_adjustment >= 0, "");
 722               try_next_mask = true;
 723               break;
 724             }
 725           }
 726         }
 727       }
 728 
 729       // Verify stack depth and oops in frame
 730       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
 731       if (!(
 732             /* SPARC */
 733             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
 734             /* x86 */
 735             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
 736             (try_next_mask &&
 737              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
 738                                                                     top_frame_expression_stack_adjustment))) ||
 739             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
 740             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
 741              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
 742             )) {
 743         ttyLocker ttyl;
 744 
 745         // Print out some information that will help us debug the problem
 746         tty->print_cr("Wrong number of expression stack elements during deoptimization");
 747         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
 748         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
 749                       iframe->interpreter_frame_expression_stack_size());
 750         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
 751         tty->print_cr("  try_next_mask = %d", try_next_mask);
 752         tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
 753         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
 754         tty->print_cr("  callee_max_locals = %d", callee_max_locals);
 755         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
 756         tty->print_cr("  exec_mode = %d", exec_mode);
 757         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
 758         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
 759         tty->print_cr("  Interpreted frames:");
 760         for (int k = 0; k < cur_array->frames(); k++) {
 761           vframeArrayElement* el = cur_array->element(k);
 762           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
 763         }
 764         cur_array->print_on_2(tty);
 765         guarantee(false, "wrong number of expression stack elements during deopt");
 766       }
 767       VerifyOopClosure verify;
 768       iframe->oops_interpreted_do(&verify, NULL, &rm, false);
 769       callee_size_of_parameters = mh->size_of_parameters();
 770       callee_max_locals = mh->max_locals();
 771       is_top_frame = false;
 772     }
 773   }
 774 #endif /* !PRODUCT */
 775 
 776 
 777   return bt;
 778 JRT_END
 779 
 780 
 781 int Deoptimization::deoptimize_dependents() {
 782   Threads::deoptimized_wrt_marked_nmethods();
 783   return 0;
 784 }
 785 
 786 Deoptimization::DeoptAction Deoptimization::_unloaded_action
 787   = Deoptimization::Action_reinterpret;
 788 
 789 #if defined(COMPILER2) || INCLUDE_JVMCI
 790 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
 791   Handle pending_exception(thread->pending_exception());
 792   const char* exception_file = thread->exception_file();
 793   int exception_line = thread->exception_line();
 794   thread->clear_pending_exception();
 795 
 796   bool failures = false;
 797 
 798   for (int i = 0; i < objects->length(); i++) {
 799     assert(objects->at(i)->is_object(), "invalid debug information");
 800     ObjectValue* sv = (ObjectValue*) objects->at(i);
 801 
 802     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 803     oop obj = NULL;
 804 
 805     if (k->is_instance_klass()) {
 806       InstanceKlass* ik = InstanceKlass::cast(k());
 807       obj = ik->allocate_instance(THREAD);
 808     } else if (k->is_typeArray_klass()) {
 809       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
 810       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
 811       int len = sv->field_size() / type2size[ak->element_type()];
 812       obj = ak->allocate(len, THREAD);
 813     } else if (k->is_objArray_klass()) {
 814       ObjArrayKlass* ak = ObjArrayKlass::cast(k());
 815       obj = ak->allocate(sv->field_size(), THREAD);
 816     }
 817 
 818     if (obj == NULL) {
 819       failures = true;
 820     }
 821 
 822     assert(sv->value().is_null(), "redundant reallocation");
 823     assert(obj != NULL || HAS_PENDING_EXCEPTION, "allocation should succeed or we should get an exception");
 824     CLEAR_PENDING_EXCEPTION;
 825     sv->set_value(obj);
 826   }
 827 
 828   if (failures) {
 829     THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
 830   } else if (pending_exception.not_null()) {
 831     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
 832   }
 833 
 834   return failures;
 835 }
 836 
 837 // restore elements of an eliminated type array
 838 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
 839   int index = 0;
 840   intptr_t val;
 841 
 842   for (int i = 0; i < sv->field_size(); i++) {
 843     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 844     switch(type) {
 845     case T_LONG: case T_DOUBLE: {
 846       assert(value->type() == T_INT, "Agreement.");
 847       StackValue* low =
 848         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
 849 #ifdef _LP64
 850       jlong res = (jlong)low->get_int();
 851 #else
 852 #ifdef SPARC
 853       // For SPARC we have to swap high and low words.
 854       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 855 #else
 856       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 857 #endif //SPARC
 858 #endif
 859       obj->long_at_put(index, res);
 860       break;
 861     }
 862 
 863     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 864     case T_INT: case T_FLOAT: { // 4 bytes.
 865       assert(value->type() == T_INT, "Agreement.");
 866       bool big_value = false;
 867       if (i + 1 < sv->field_size() && type == T_INT) {
 868         if (sv->field_at(i)->is_location()) {
 869           Location::Type type = ((LocationValue*) sv->field_at(i))->location().type();
 870           if (type == Location::dbl || type == Location::lng) {
 871             big_value = true;
 872           }
 873         } else if (sv->field_at(i)->is_constant_int()) {
 874           ScopeValue* next_scope_field = sv->field_at(i + 1);
 875           if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
 876             big_value = true;
 877           }
 878         }
 879       }
 880 
 881       if (big_value) {
 882         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
 883   #ifdef _LP64
 884         jlong res = (jlong)low->get_int();
 885   #else
 886   #ifdef SPARC
 887         // For SPARC we have to swap high and low words.
 888         jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 889   #else
 890         jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 891   #endif //SPARC
 892   #endif
 893         obj->int_at_put(index, (jint)*((jint*)&res));
 894         obj->int_at_put(++index, (jint)*(((jint*)&res) + 1));
 895       } else {
 896         val = value->get_int();
 897         obj->int_at_put(index, (jint)*((jint*)&val));
 898       }
 899       break;
 900     }
 901 
 902     case T_SHORT: case T_CHAR: // 2 bytes
 903       assert(value->type() == T_INT, "Agreement.");
 904       val = value->get_int();
 905       obj->short_at_put(index, (jshort)*((jint*)&val));
 906       break;
 907 
 908     case T_BOOLEAN: case T_BYTE: // 1 byte
 909       assert(value->type() == T_INT, "Agreement.");
 910       val = value->get_int();
 911       obj->bool_at_put(index, (jboolean)*((jint*)&val));
 912       break;
 913 
 914       default:
 915         ShouldNotReachHere();
 916     }
 917     index++;
 918   }
 919 }
 920 
 921 
 922 // restore fields of an eliminated object array
 923 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
 924   for (int i = 0; i < sv->field_size(); i++) {
 925     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 926     assert(value->type() == T_OBJECT, "object element expected");
 927     obj->obj_at_put(i, value->get_obj()());
 928   }
 929 }
 930 
 931 class ReassignedField {
 932 public:
 933   int _offset;
 934   BasicType _type;
 935   InstanceKlass* _klass;
 936 public:
 937   ReassignedField() {
 938     _offset = 0;
 939     _type = T_ILLEGAL;
 940     _klass = NULL;
 941   }
 942 };
 943 
 944 int compare(ReassignedField* left, ReassignedField* right) {
 945   return left->_offset - right->_offset;
 946 }
 947 
 948 // Restore fields of an eliminated instance object using the same field order
 949 // returned by HotSpotResolvedObjectTypeImpl.getInstanceFields(true)
 950 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, bool skip_internal, int base_offset, TRAPS) {
 951   if (klass->superklass() != NULL) {
 952     svIndex = reassign_fields_by_klass(klass->superklass(), fr, reg_map, sv, svIndex, obj, skip_internal, 0, CHECK_0);
 953   }
 954 
 955   GrowableArray<ReassignedField>* fields = new GrowableArray<ReassignedField>();
 956   for (AllFieldStream fs(klass); !fs.done(); fs.next()) {
 957     if (!fs.access_flags().is_static() && (!skip_internal || !fs.access_flags().is_internal())) {
 958       ReassignedField field;
 959       field._offset = fs.offset();
 960       field._type = FieldType::basic_type(fs.signature());
 961       if (field._type == T_VALUETYPE) {
 962         // Resolve klass of flattened value type field
 963         SignatureStream ss(fs.signature(), false);
 964         Klass* vk = ss.as_klass(Handle(klass->class_loader()), Handle(klass->protection_domain()), SignatureStream::NCDFError, THREAD);
 965         guarantee(!HAS_PENDING_EXCEPTION, "Should not have any exceptions pending");
 966         assert(vk->is_value(), "must be a ValueKlass");
 967         field._klass = InstanceKlass::cast(vk);
 968       }
 969       fields->append(field);
 970     }
 971   }
 972   fields->sort(compare);
 973   for (int i = 0; i < fields->length(); i++) {
 974     intptr_t val;
 975     ScopeValue* scope_field = sv->field_at(svIndex);
 976     StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
 977     int offset = base_offset + fields->at(i)._offset;
 978     BasicType type = fields->at(i)._type;
 979     switch (type) {
 980       case T_OBJECT: case T_ARRAY:
 981         assert(value->type() == T_OBJECT, "Agreement.");
 982         obj->obj_field_put(offset, value->get_obj()());
 983         break;
 984 
 985       case T_VALUETYPE: {
 986         // Recursively re-assign flattened value type fields
 987         InstanceKlass* vk = fields->at(i)._klass;
 988         assert(vk != NULL, "must be resolved");
 989         offset -= ValueKlass::cast(vk)->first_field_offset(); // Adjust offset to omit oop header
 990         svIndex = reassign_fields_by_klass(vk, fr, reg_map, sv, svIndex, obj, skip_internal, offset, CHECK_0);
 991         continue; // Continue because we don't need to increment svIndex
 992       }
 993 
 994       // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 995       case T_INT: case T_FLOAT: { // 4 bytes.
 996         assert(value->type() == T_INT, "Agreement.");
 997         bool big_value = false;
 998         if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
 999           if (scope_field->is_location()) {
1000             Location::Type type = ((LocationValue*) scope_field)->location().type();
1001             if (type == Location::dbl || type == Location::lng) {
1002               big_value = true;
1003             }
1004           }
1005           if (scope_field->is_constant_int()) {
1006             ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
1007             if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1008               big_value = true;
1009             }
1010           }
1011         }
1012 
1013         if (big_value) {
1014           i++;
1015           assert(i < fields->length(), "second T_INT field needed");
1016           assert(fields->at(i)._type == T_INT, "T_INT field needed");
1017         } else {
1018           val = value->get_int();
1019           obj->int_field_put(offset, (jint)*((jint*)&val));
1020           break;
1021         }
1022       }
1023         /* no break */
1024 
1025       case T_LONG: case T_DOUBLE: {
1026         assert(value->type() == T_INT, "Agreement.");
1027         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
1028 #ifdef _LP64
1029         jlong res = (jlong)low->get_int();
1030 #else
1031 #ifdef SPARC
1032         // For SPARC we have to swap high and low words.
1033         jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
1034 #else
1035         jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
1036 #endif //SPARC
1037 #endif
1038         obj->long_field_put(offset, res);
1039         break;
1040       }
1041 
1042       case T_SHORT: case T_CHAR: // 2 bytes
1043         assert(value->type() == T_INT, "Agreement.");
1044         val = value->get_int();
1045         obj->short_field_put(offset, (jshort)*((jint*)&val));
1046         break;
1047 
1048       case T_BOOLEAN: case T_BYTE: // 1 byte
1049         assert(value->type() == T_INT, "Agreement.");
1050         val = value->get_int();
1051         obj->bool_field_put(offset, (jboolean)*((jint*)&val));
1052         break;
1053 
1054       default:
1055         ShouldNotReachHere();
1056     }
1057     svIndex++;
1058   }
1059   return svIndex;
1060 }
1061 
1062 // restore fields of all eliminated objects and arrays
1063 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal, TRAPS) {
1064   for (int i = 0; i < objects->length(); i++) {
1065     ObjectValue* sv = (ObjectValue*) objects->at(i);
1066     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
1067     Handle obj = sv->value();
1068     assert(obj.not_null() || realloc_failures, "reallocation was missed");
1069     if (PrintDeoptimizationDetails) {
1070       tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1071     }
1072     if (obj.is_null()) {
1073       continue;
1074     }
1075 
1076     if (k->is_instance_klass()) {
1077       InstanceKlass* ik = InstanceKlass::cast(k());
1078       reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), skip_internal, 0, CHECK);
1079     } else if (k->is_typeArray_klass()) {
1080       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
1081       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1082     } else if (k->is_objArray_klass()) {
1083       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1084     }
1085   }
1086 }
1087 
1088 
1089 // relock objects for which synchronization was eliminated
1090 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures) {
1091   for (int i = 0; i < monitors->length(); i++) {
1092     MonitorInfo* mon_info = monitors->at(i);
1093     if (mon_info->eliminated()) {
1094       assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1095       if (!mon_info->owner_is_scalar_replaced()) {
1096         Handle obj = Handle(mon_info->owner());
1097         markOop mark = obj->mark();
1098         if (UseBiasedLocking && mark->has_bias_pattern()) {
1099           // New allocated objects may have the mark set to anonymously biased.
1100           // Also the deoptimized method may called methods with synchronization
1101           // where the thread-local object is bias locked to the current thread.
1102           assert(mark->is_biased_anonymously() ||
1103                  mark->biased_locker() == thread, "should be locked to current thread");
1104           // Reset mark word to unbiased prototype.
1105           markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
1106           obj->set_mark(unbiased_prototype);
1107         }
1108         BasicLock* lock = mon_info->lock();
1109         ObjectSynchronizer::slow_enter(obj, lock, thread);
1110         assert(mon_info->owner()->is_locked(), "object must be locked now");
1111       }
1112     }
1113   }
1114 }
1115 
1116 
1117 #ifndef PRODUCT
1118 // print information about reallocated objects
1119 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
1120   fieldDescriptor fd;
1121 
1122   for (int i = 0; i < objects->length(); i++) {
1123     ObjectValue* sv = (ObjectValue*) objects->at(i);
1124     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
1125     Handle obj = sv->value();
1126 
1127     tty->print("     object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
1128     k->print_value();
1129     assert(obj.not_null() || realloc_failures, "reallocation was missed");
1130     if (obj.is_null()) {
1131       tty->print(" allocation failed");
1132     } else {
1133       tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
1134     }
1135     tty->cr();
1136 
1137     if (Verbose && !obj.is_null()) {
1138       k->oop_print_on(obj(), tty);
1139     }
1140   }
1141 }
1142 #endif
1143 #endif // COMPILER2 || INCLUDE_JVMCI
1144 
1145 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1146   Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1147 
1148 #ifndef PRODUCT
1149   if (PrintDeoptimizationDetails) {
1150     ttyLocker ttyl;
1151     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", p2i(thread));
1152     fr.print_on(tty);
1153     tty->print_cr("     Virtual frames (innermost first):");
1154     for (int index = 0; index < chunk->length(); index++) {
1155       compiledVFrame* vf = chunk->at(index);
1156       tty->print("       %2d - ", index);
1157       vf->print_value();
1158       int bci = chunk->at(index)->raw_bci();
1159       const char* code_name;
1160       if (bci == SynchronizationEntryBCI) {
1161         code_name = "sync entry";
1162       } else {
1163         Bytecodes::Code code = vf->method()->code_at(bci);
1164         code_name = Bytecodes::name(code);
1165       }
1166       tty->print(" - %s", code_name);
1167       tty->print_cr(" @ bci %d ", bci);
1168       if (Verbose) {
1169         vf->print();
1170         tty->cr();
1171       }
1172     }
1173   }
1174 #endif
1175 
1176   // Register map for next frame (used for stack crawl).  We capture
1177   // the state of the deopt'ing frame's caller.  Thus if we need to
1178   // stuff a C2I adapter we can properly fill in the callee-save
1179   // register locations.
1180   frame caller = fr.sender(reg_map);
1181   int frame_size = caller.sp() - fr.sp();
1182 
1183   frame sender = caller;
1184 
1185   // Since the Java thread being deoptimized will eventually adjust it's own stack,
1186   // the vframeArray containing the unpacking information is allocated in the C heap.
1187   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1188   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1189 
1190   // Compare the vframeArray to the collected vframes
1191   assert(array->structural_compare(thread, chunk), "just checking");
1192 
1193 #ifndef PRODUCT
1194   if (PrintDeoptimizationDetails) {
1195     ttyLocker ttyl;
1196     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, p2i(array));
1197   }
1198 #endif // PRODUCT
1199 
1200   return array;
1201 }
1202 
1203 #if defined(COMPILER2) || INCLUDE_JVMCI
1204 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1205   // Reallocation of some scalar replaced objects failed. Record
1206   // that we need to pop all the interpreter frames for the
1207   // deoptimized compiled frame.
1208   assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1209   thread->set_frames_to_pop_failed_realloc(array->frames());
1210   // Unlock all monitors here otherwise the interpreter will see a
1211   // mix of locked and unlocked monitors (because of failed
1212   // reallocations of synchronized objects) and be confused.
1213   for (int i = 0; i < array->frames(); i++) {
1214     MonitorChunk* monitors = array->element(i)->monitors();
1215     if (monitors != NULL) {
1216       for (int j = 0; j < monitors->number_of_monitors(); j++) {
1217         BasicObjectLock* src = monitors->at(j);
1218         if (src->obj() != NULL) {
1219           ObjectSynchronizer::fast_exit(src->obj(), src->lock(), thread);
1220         }
1221       }
1222       array->element(i)->free_monitors(thread);
1223 #ifdef ASSERT
1224       array->element(i)->set_removed_monitors();
1225 #endif
1226     }
1227   }
1228 }
1229 #endif
1230 
1231 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1232   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1233   for (int i = 0; i < monitors->length(); i++) {
1234     MonitorInfo* mon_info = monitors->at(i);
1235     if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1236       objects_to_revoke->append(Handle(mon_info->owner()));
1237     }
1238   }
1239 }
1240 
1241 
1242 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1243   if (!UseBiasedLocking) {
1244     return;
1245   }
1246 
1247   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1248 
1249   // Unfortunately we don't have a RegisterMap available in most of
1250   // the places we want to call this routine so we need to walk the
1251   // stack again to update the register map.
1252   if (map == NULL || !map->update_map()) {
1253     StackFrameStream sfs(thread, true);
1254     bool found = false;
1255     while (!found && !sfs.is_done()) {
1256       frame* cur = sfs.current();
1257       sfs.next();
1258       found = cur->id() == fr.id();
1259     }
1260     assert(found, "frame to be deoptimized not found on target thread's stack");
1261     map = sfs.register_map();
1262   }
1263 
1264   vframe* vf = vframe::new_vframe(&fr, map, thread);
1265   compiledVFrame* cvf = compiledVFrame::cast(vf);
1266   // Revoke monitors' biases in all scopes
1267   while (!cvf->is_top()) {
1268     collect_monitors(cvf, objects_to_revoke);
1269     cvf = compiledVFrame::cast(cvf->sender());
1270   }
1271   collect_monitors(cvf, objects_to_revoke);
1272 
1273   if (SafepointSynchronize::is_at_safepoint()) {
1274     BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1275   } else {
1276     BiasedLocking::revoke(objects_to_revoke);
1277   }
1278 }
1279 
1280 
1281 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1282   if (!UseBiasedLocking) {
1283     return;
1284   }
1285 
1286   assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1287   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1288   for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1289     if (jt->has_last_Java_frame()) {
1290       StackFrameStream sfs(jt, true);
1291       while (!sfs.is_done()) {
1292         frame* cur = sfs.current();
1293         if (cb->contains(cur->pc())) {
1294           vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1295           compiledVFrame* cvf = compiledVFrame::cast(vf);
1296           // Revoke monitors' biases in all scopes
1297           while (!cvf->is_top()) {
1298             collect_monitors(cvf, objects_to_revoke);
1299             cvf = compiledVFrame::cast(cvf->sender());
1300           }
1301           collect_monitors(cvf, objects_to_revoke);
1302         }
1303         sfs.next();
1304       }
1305     }
1306   }
1307   BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1308 }
1309 
1310 
1311 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1312   assert(fr.can_be_deoptimized(), "checking frame type");
1313 
1314   gather_statistics(reason, Action_none, Bytecodes::_illegal);
1315 
1316   if (LogCompilation && xtty != NULL) {
1317     nmethod* nm = fr.cb()->as_nmethod_or_null();
1318     assert(nm != NULL, "only compiled methods can deopt");
1319 
1320     ttyLocker ttyl;
1321     xtty->begin_head("deoptimized thread='" UINTX_FORMAT "'", (uintx)thread->osthread()->thread_id());
1322     nm->log_identity(xtty);
1323     xtty->end_head();
1324     for (ScopeDesc* sd = nm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1325       xtty->begin_elem("jvms bci='%d'", sd->bci());
1326       xtty->method(sd->method());
1327       xtty->end_elem();
1328       if (sd->is_top())  break;
1329     }
1330     xtty->tail("deoptimized");
1331   }
1332 
1333   // Patch the compiled method so that when execution returns to it we will
1334   // deopt the execution state and return to the interpreter.
1335   fr.deoptimize(thread);
1336 }
1337 
1338 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1339   deoptimize(thread, fr, map, Reason_constraint);
1340 }
1341 
1342 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map, DeoptReason reason) {
1343   // Deoptimize only if the frame comes from compile code.
1344   // Do not deoptimize the frame which is already patched
1345   // during the execution of the loops below.
1346   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1347     return;
1348   }
1349   ResourceMark rm;
1350   DeoptimizationMarker dm;
1351   if (UseBiasedLocking) {
1352     revoke_biases_of_monitors(thread, fr, map);
1353   }
1354   deoptimize_single_frame(thread, fr, reason);
1355 
1356 }
1357 
1358 
1359 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1360   assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1361          "can only deoptimize other thread at a safepoint");
1362   // Compute frame and register map based on thread and sp.
1363   RegisterMap reg_map(thread, UseBiasedLocking);
1364   frame fr = thread->last_frame();
1365   while (fr.id() != id) {
1366     fr = fr.sender(&reg_map);
1367   }
1368   deoptimize(thread, fr, &reg_map, reason);
1369 }
1370 
1371 
1372 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1373   if (thread == Thread::current()) {
1374     Deoptimization::deoptimize_frame_internal(thread, id, reason);
1375   } else {
1376     VM_DeoptimizeFrame deopt(thread, id, reason);
1377     VMThread::execute(&deopt);
1378   }
1379 }
1380 
1381 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1382   deoptimize_frame(thread, id, Reason_constraint);
1383 }
1384 
1385 // JVMTI PopFrame support
1386 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1387 {
1388   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1389 }
1390 JRT_END
1391 
1392 MethodData*
1393 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1394                                 bool create_if_missing) {
1395   Thread* THREAD = thread;
1396   MethodData* mdo = m()->method_data();
1397   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1398     // Build an MDO.  Ignore errors like OutOfMemory;
1399     // that simply means we won't have an MDO to update.
1400     Method::build_interpreter_method_data(m, THREAD);
1401     if (HAS_PENDING_EXCEPTION) {
1402       assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1403       CLEAR_PENDING_EXCEPTION;
1404     }
1405     mdo = m()->method_data();
1406   }
1407   return mdo;
1408 }
1409 
1410 #if defined(COMPILER2) || defined(SHARK) || INCLUDE_JVMCI
1411 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS) {
1412   // in case of an unresolved klass entry, load the class.
1413   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1414     Klass* tk = constant_pool->klass_at_ignore_error(index, CHECK);
1415     return;
1416   }
1417 
1418   if (!constant_pool->tag_at(index).is_symbol()) return;
1419 
1420   Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1421   Symbol*  symbol  = constant_pool->symbol_at(index);
1422 
1423   // class name?
1424   if (symbol->byte_at(0) != '(') {
1425     Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1426     SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1427     return;
1428   }
1429 
1430   // then it must be a signature!
1431   ResourceMark rm(THREAD);
1432   for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1433     if (ss.is_object()) {
1434       Symbol* class_name = ss.as_symbol(CHECK);
1435       Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1436       SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1437     }
1438   }
1439 }
1440 
1441 
1442 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index) {
1443   EXCEPTION_MARK;
1444   load_class_by_index(constant_pool, index, THREAD);
1445   if (HAS_PENDING_EXCEPTION) {
1446     // Exception happened during classloading. We ignore the exception here, since it
1447     // is going to be rethrown since the current activation is going to be deoptimized and
1448     // the interpreter will re-execute the bytecode.
1449     CLEAR_PENDING_EXCEPTION;
1450     // Class loading called java code which may have caused a stack
1451     // overflow. If the exception was thrown right before the return
1452     // to the runtime the stack is no longer guarded. Reguard the
1453     // stack otherwise if we return to the uncommon trap blob and the
1454     // stack bang causes a stack overflow we crash.
1455     assert(THREAD->is_Java_thread(), "only a java thread can be here");
1456     JavaThread* thread = (JavaThread*)THREAD;
1457     bool guard_pages_enabled = thread->stack_guards_enabled();
1458     if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1459     assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1460   }
1461 }
1462 
1463 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1464   HandleMark hm;
1465 
1466   // uncommon_trap() is called at the beginning of the uncommon trap
1467   // handler. Note this fact before we start generating temporary frames
1468   // that can confuse an asynchronous stack walker. This counter is
1469   // decremented at the end of unpack_frames().
1470   thread->inc_in_deopt_handler();
1471 
1472   // We need to update the map if we have biased locking.
1473 #if INCLUDE_JVMCI
1474   // JVMCI might need to get an exception from the stack, which in turn requires the register map to be valid
1475   RegisterMap reg_map(thread, true);
1476 #else
1477   RegisterMap reg_map(thread, UseBiasedLocking);
1478 #endif
1479   frame stub_frame = thread->last_frame();
1480   frame fr = stub_frame.sender(&reg_map);
1481   // Make sure the calling nmethod is not getting deoptimized and removed
1482   // before we are done with it.
1483   nmethodLocker nl(fr.pc());
1484 
1485   // Log a message
1486   Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
1487               trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
1488 
1489   {
1490     ResourceMark rm;
1491 
1492     // Revoke biases of any monitors in the frame to ensure we can migrate them
1493     revoke_biases_of_monitors(thread, fr, &reg_map);
1494 
1495     DeoptReason reason = trap_request_reason(trap_request);
1496     DeoptAction action = trap_request_action(trap_request);
1497 #if INCLUDE_JVMCI
1498     int debug_id = trap_request_debug_id(trap_request);
1499 #endif
1500     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1501 
1502     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, thread);
1503     compiledVFrame* cvf = compiledVFrame::cast(vf);
1504 
1505     nmethod* nm = cvf->code();
1506 
1507     ScopeDesc*      trap_scope  = cvf->scope();
1508 
1509     if (TraceDeoptimization) {
1510       ttyLocker ttyl;
1511       tty->print_cr("  bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s" JVMCI_ONLY(", debug_id=%d"), trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string()
1512 #if INCLUDE_JVMCI
1513           , debug_id
1514 #endif
1515           );
1516     }
1517 
1518     methodHandle    trap_method = trap_scope->method();
1519     int             trap_bci    = trap_scope->bci();
1520 #if INCLUDE_JVMCI
1521     oop speculation = thread->pending_failed_speculation();
1522     if (nm->is_compiled_by_jvmci()) {
1523       if (speculation != NULL) {
1524         oop speculation_log = nm->speculation_log();
1525         if (speculation_log != NULL) {
1526           if (TraceDeoptimization || TraceUncollectedSpeculations) {
1527             if (HotSpotSpeculationLog::lastFailed(speculation_log) != NULL) {
1528               tty->print_cr("A speculation that was not collected by the compiler is being overwritten");
1529             }
1530           }
1531           if (TraceDeoptimization) {
1532             tty->print_cr("Saving speculation to speculation log");
1533           }
1534           HotSpotSpeculationLog::set_lastFailed(speculation_log, speculation);
1535         } else {
1536           if (TraceDeoptimization) {
1537             tty->print_cr("Speculation present but no speculation log");
1538           }
1539         }
1540         thread->set_pending_failed_speculation(NULL);
1541       } else {
1542         if (TraceDeoptimization) {
1543           tty->print_cr("No speculation");
1544         }
1545       }
1546     } else {
1547       assert(speculation == NULL, "There should not be a speculation for method compiled by non-JVMCI compilers");
1548     }
1549 
1550     if (trap_bci == SynchronizationEntryBCI) {
1551       trap_bci = 0;
1552       thread->set_pending_monitorenter(true);
1553     }
1554 
1555     if (reason == Deoptimization::Reason_transfer_to_interpreter) {
1556       thread->set_pending_transfer_to_interpreter(true);
1557     }
1558 #endif
1559 
1560     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
1561     // Record this event in the histogram.
1562     gather_statistics(reason, action, trap_bc);
1563 
1564     // Ensure that we can record deopt. history:
1565     // Need MDO to record RTM code generation state.
1566     bool create_if_missing = ProfileTraps || UseCodeAging RTM_OPT_ONLY( || UseRTMLocking );
1567 
1568     methodHandle profiled_method;
1569 #if INCLUDE_JVMCI
1570     if (nm->is_compiled_by_jvmci()) {
1571       profiled_method = nm->method();
1572     } else {
1573       profiled_method = trap_method;
1574     }
1575 #else
1576     profiled_method = trap_method;
1577 #endif
1578 
1579     MethodData* trap_mdo =
1580       get_method_data(thread, profiled_method, create_if_missing);
1581 
1582     // Log a message
1583     Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1584                               trap_reason_name(reason), trap_action_name(action), p2i(fr.pc()),
1585                               trap_method->name_and_sig_as_C_string(), trap_bci);
1586 
1587     // Print a bunch of diagnostics, if requested.
1588     if (TraceDeoptimization || LogCompilation) {
1589       ResourceMark rm;
1590       ttyLocker ttyl;
1591       char buf[100];
1592       if (xtty != NULL) {
1593         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT "' %s",
1594                          os::current_thread_id(),
1595                          format_trap_request(buf, sizeof(buf), trap_request));
1596         nm->log_identity(xtty);
1597       }
1598       Symbol* class_name = NULL;
1599       bool unresolved = false;
1600       if (unloaded_class_index >= 0) {
1601         constantPoolHandle constants (THREAD, trap_method->constants());
1602         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1603           class_name = constants->klass_name_at(unloaded_class_index);
1604           unresolved = true;
1605           if (xtty != NULL)
1606             xtty->print(" unresolved='1'");
1607         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1608           class_name = constants->symbol_at(unloaded_class_index);
1609         }
1610         if (xtty != NULL)
1611           xtty->name(class_name);
1612       }
1613       if (xtty != NULL && trap_mdo != NULL && (int)reason < (int)MethodData::_trap_hist_limit) {
1614         // Dump the relevant MDO state.
1615         // This is the deopt count for the current reason, any previous
1616         // reasons or recompiles seen at this point.
1617         int dcnt = trap_mdo->trap_count(reason);
1618         if (dcnt != 0)
1619           xtty->print(" count='%d'", dcnt);
1620         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1621         int dos = (pdata == NULL)? 0: pdata->trap_state();
1622         if (dos != 0) {
1623           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1624           if (trap_state_is_recompiled(dos)) {
1625             int recnt2 = trap_mdo->overflow_recompile_count();
1626             if (recnt2 != 0)
1627               xtty->print(" recompiles2='%d'", recnt2);
1628           }
1629         }
1630       }
1631       if (xtty != NULL) {
1632         xtty->stamp();
1633         xtty->end_head();
1634       }
1635       if (TraceDeoptimization) {  // make noise on the tty
1636         tty->print("Uncommon trap occurred in");
1637         nm->method()->print_short_name(tty);
1638         tty->print(" compiler=%s compile_id=%d", nm->compiler() == NULL ? "" : nm->compiler()->name(), nm->compile_id());
1639 #if INCLUDE_JVMCI
1640         oop installedCode = nm->jvmci_installed_code();
1641         if (installedCode != NULL) {
1642           oop installedCodeName = NULL;
1643           if (installedCode->is_a(InstalledCode::klass())) {
1644             installedCodeName = InstalledCode::name(installedCode);
1645           }
1646           if (installedCodeName != NULL) {
1647             tty->print(" (JVMCI: installedCodeName=%s) ", java_lang_String::as_utf8_string(installedCodeName));
1648           } else {
1649             tty->print(" (JVMCI: installed code has no name) ");
1650           }
1651         } else if (nm->is_compiled_by_jvmci()) {
1652           tty->print(" (JVMCI: no installed code) ");
1653         }
1654 #endif
1655         tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d" JVMCI_ONLY(" debug_id=%d"),
1656                    p2i(fr.pc()),
1657                    os::current_thread_id(),
1658                    trap_reason_name(reason),
1659                    trap_action_name(action),
1660                    unloaded_class_index
1661 #if INCLUDE_JVMCI
1662                    , debug_id
1663 #endif
1664                    );
1665         if (class_name != NULL) {
1666           tty->print(unresolved ? " unresolved class: " : " symbol: ");
1667           class_name->print_symbol_on(tty);
1668         }
1669         tty->cr();
1670       }
1671       if (xtty != NULL) {
1672         // Log the precise location of the trap.
1673         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1674           xtty->begin_elem("jvms bci='%d'", sd->bci());
1675           xtty->method(sd->method());
1676           xtty->end_elem();
1677           if (sd->is_top())  break;
1678         }
1679         xtty->tail("uncommon_trap");
1680       }
1681     }
1682     // (End diagnostic printout.)
1683 
1684     // Load class if necessary
1685     if (unloaded_class_index >= 0) {
1686       constantPoolHandle constants(THREAD, trap_method->constants());
1687       load_class_by_index(constants, unloaded_class_index);
1688     }
1689 
1690     // Flush the nmethod if necessary and desirable.
1691     //
1692     // We need to avoid situations where we are re-flushing the nmethod
1693     // because of a hot deoptimization site.  Repeated flushes at the same
1694     // point need to be detected by the compiler and avoided.  If the compiler
1695     // cannot avoid them (or has a bug and "refuses" to avoid them), this
1696     // module must take measures to avoid an infinite cycle of recompilation
1697     // and deoptimization.  There are several such measures:
1698     //
1699     //   1. If a recompilation is ordered a second time at some site X
1700     //   and for the same reason R, the action is adjusted to 'reinterpret',
1701     //   to give the interpreter time to exercise the method more thoroughly.
1702     //   If this happens, the method's overflow_recompile_count is incremented.
1703     //
1704     //   2. If the compiler fails to reduce the deoptimization rate, then
1705     //   the method's overflow_recompile_count will begin to exceed the set
1706     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
1707     //   is adjusted to 'make_not_compilable', and the method is abandoned
1708     //   to the interpreter.  This is a performance hit for hot methods,
1709     //   but is better than a disastrous infinite cycle of recompilations.
1710     //   (Actually, only the method containing the site X is abandoned.)
1711     //
1712     //   3. In parallel with the previous measures, if the total number of
1713     //   recompilations of a method exceeds the much larger set limit
1714     //   PerMethodRecompilationCutoff, the method is abandoned.
1715     //   This should only happen if the method is very large and has
1716     //   many "lukewarm" deoptimizations.  The code which enforces this
1717     //   limit is elsewhere (class nmethod, class Method).
1718     //
1719     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1720     // to recompile at each bytecode independently of the per-BCI cutoff.
1721     //
1722     // The decision to update code is up to the compiler, and is encoded
1723     // in the Action_xxx code.  If the compiler requests Action_none
1724     // no trap state is changed, no compiled code is changed, and the
1725     // computation suffers along in the interpreter.
1726     //
1727     // The other action codes specify various tactics for decompilation
1728     // and recompilation.  Action_maybe_recompile is the loosest, and
1729     // allows the compiled code to stay around until enough traps are seen,
1730     // and until the compiler gets around to recompiling the trapping method.
1731     //
1732     // The other actions cause immediate removal of the present code.
1733 
1734     // Traps caused by injected profile shouldn't pollute trap counts.
1735     bool injected_profile_trap = trap_method->has_injected_profile() &&
1736                                  (reason == Reason_intrinsic || reason == Reason_unreached);
1737 
1738     bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
1739     bool make_not_entrant = false;
1740     bool make_not_compilable = false;
1741     bool reprofile = false;
1742     switch (action) {
1743     case Action_none:
1744       // Keep the old code.
1745       update_trap_state = false;
1746       break;
1747     case Action_maybe_recompile:
1748       // Do not need to invalidate the present code, but we can
1749       // initiate another
1750       // Start compiler without (necessarily) invalidating the nmethod.
1751       // The system will tolerate the old code, but new code should be
1752       // generated when possible.
1753       break;
1754     case Action_reinterpret:
1755       // Go back into the interpreter for a while, and then consider
1756       // recompiling form scratch.
1757       make_not_entrant = true;
1758       // Reset invocation counter for outer most method.
1759       // This will allow the interpreter to exercise the bytecodes
1760       // for a while before recompiling.
1761       // By contrast, Action_make_not_entrant is immediate.
1762       //
1763       // Note that the compiler will track null_check, null_assert,
1764       // range_check, and class_check events and log them as if they
1765       // had been traps taken from compiled code.  This will update
1766       // the MDO trap history so that the next compilation will
1767       // properly detect hot trap sites.
1768       reprofile = true;
1769       break;
1770     case Action_make_not_entrant:
1771       // Request immediate recompilation, and get rid of the old code.
1772       // Make them not entrant, so next time they are called they get
1773       // recompiled.  Unloaded classes are loaded now so recompile before next
1774       // time they are called.  Same for uninitialized.  The interpreter will
1775       // link the missing class, if any.
1776       make_not_entrant = true;
1777       break;
1778     case Action_make_not_compilable:
1779       // Give up on compiling this method at all.
1780       make_not_entrant = true;
1781       make_not_compilable = true;
1782       break;
1783     default:
1784       ShouldNotReachHere();
1785     }
1786 
1787     // Setting +ProfileTraps fixes the following, on all platforms:
1788     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
1789     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1790     // recompile relies on a MethodData* to record heroic opt failures.
1791 
1792     // Whether the interpreter is producing MDO data or not, we also need
1793     // to use the MDO to detect hot deoptimization points and control
1794     // aggressive optimization.
1795     bool inc_recompile_count = false;
1796     ProfileData* pdata = NULL;
1797     if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1798       assert(trap_mdo == get_method_data(thread, profiled_method, false), "sanity");
1799       uint this_trap_count = 0;
1800       bool maybe_prior_trap = false;
1801       bool maybe_prior_recompile = false;
1802       pdata = query_update_method_data(trap_mdo, trap_bci, reason, true,
1803 #if INCLUDE_JVMCI
1804                                    nm->is_compiled_by_jvmci() && nm->is_osr_method(),
1805 #endif
1806                                    nm->method(),
1807                                    //outputs:
1808                                    this_trap_count,
1809                                    maybe_prior_trap,
1810                                    maybe_prior_recompile);
1811       // Because the interpreter also counts null, div0, range, and class
1812       // checks, these traps from compiled code are double-counted.
1813       // This is harmless; it just means that the PerXTrapLimit values
1814       // are in effect a little smaller than they look.
1815 
1816       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1817       if (per_bc_reason != Reason_none) {
1818         // Now take action based on the partially known per-BCI history.
1819         if (maybe_prior_trap
1820             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1821           // If there are too many traps at this BCI, force a recompile.
1822           // This will allow the compiler to see the limit overflow, and
1823           // take corrective action, if possible.  The compiler generally
1824           // does not use the exact PerBytecodeTrapLimit value, but instead
1825           // changes its tactics if it sees any traps at all.  This provides
1826           // a little hysteresis, delaying a recompile until a trap happens
1827           // several times.
1828           //
1829           // Actually, since there is only one bit of counter per BCI,
1830           // the possible per-BCI counts are {0,1,(per-method count)}.
1831           // This produces accurate results if in fact there is only
1832           // one hot trap site, but begins to get fuzzy if there are
1833           // many sites.  For example, if there are ten sites each
1834           // trapping two or more times, they each get the blame for
1835           // all of their traps.
1836           make_not_entrant = true;
1837         }
1838 
1839         // Detect repeated recompilation at the same BCI, and enforce a limit.
1840         if (make_not_entrant && maybe_prior_recompile) {
1841           // More than one recompile at this point.
1842           inc_recompile_count = maybe_prior_trap;
1843         }
1844       } else {
1845         // For reasons which are not recorded per-bytecode, we simply
1846         // force recompiles unconditionally.
1847         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1848         make_not_entrant = true;
1849       }
1850 
1851       // Go back to the compiler if there are too many traps in this method.
1852       if (this_trap_count >= per_method_trap_limit(reason)) {
1853         // If there are too many traps in this method, force a recompile.
1854         // This will allow the compiler to see the limit overflow, and
1855         // take corrective action, if possible.
1856         // (This condition is an unlikely backstop only, because the
1857         // PerBytecodeTrapLimit is more likely to take effect first,
1858         // if it is applicable.)
1859         make_not_entrant = true;
1860       }
1861 
1862       // Here's more hysteresis:  If there has been a recompile at
1863       // this trap point already, run the method in the interpreter
1864       // for a while to exercise it more thoroughly.
1865       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1866         reprofile = true;
1867       }
1868     }
1869 
1870     // Take requested actions on the method:
1871 
1872     // Recompile
1873     if (make_not_entrant) {
1874       if (!nm->make_not_entrant()) {
1875         return; // the call did not change nmethod's state
1876       }
1877 
1878       if (pdata != NULL) {
1879         // Record the recompilation event, if any.
1880         int tstate0 = pdata->trap_state();
1881         int tstate1 = trap_state_set_recompiled(tstate0, true);
1882         if (tstate1 != tstate0)
1883           pdata->set_trap_state(tstate1);
1884       }
1885 
1886 #if INCLUDE_RTM_OPT
1887       // Restart collecting RTM locking abort statistic if the method
1888       // is recompiled for a reason other than RTM state change.
1889       // Assume that in new recompiled code the statistic could be different,
1890       // for example, due to different inlining.
1891       if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
1892           UseRTMDeopt && (nm->rtm_state() != ProfileRTM)) {
1893         trap_mdo->atomic_set_rtm_state(ProfileRTM);
1894       }
1895 #endif
1896       // For code aging we count traps separately here, using make_not_entrant()
1897       // as a guard against simultaneous deopts in multiple threads.
1898       if (reason == Reason_tenured && trap_mdo != NULL) {
1899         trap_mdo->inc_tenure_traps();
1900       }
1901     }
1902 
1903     if (inc_recompile_count) {
1904       trap_mdo->inc_overflow_recompile_count();
1905       if ((uint)trap_mdo->overflow_recompile_count() >
1906           (uint)PerBytecodeRecompilationCutoff) {
1907         // Give up on the method containing the bad BCI.
1908         if (trap_method() == nm->method()) {
1909           make_not_compilable = true;
1910         } else {
1911           trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1912           // But give grace to the enclosing nm->method().
1913         }
1914       }
1915     }
1916 
1917     // Reprofile
1918     if (reprofile) {
1919       CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1920     }
1921 
1922     // Give up compiling
1923     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1924       assert(make_not_entrant, "consistent");
1925       nm->method()->set_not_compilable(CompLevel_full_optimization);
1926     }
1927 
1928   } // Free marked resources
1929 
1930 }
1931 JRT_END
1932 
1933 ProfileData*
1934 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1935                                          int trap_bci,
1936                                          Deoptimization::DeoptReason reason,
1937                                          bool update_total_trap_count,
1938 #if INCLUDE_JVMCI
1939                                          bool is_osr,
1940 #endif
1941                                          Method* compiled_method,
1942                                          //outputs:
1943                                          uint& ret_this_trap_count,
1944                                          bool& ret_maybe_prior_trap,
1945                                          bool& ret_maybe_prior_recompile) {
1946   bool maybe_prior_trap = false;
1947   bool maybe_prior_recompile = false;
1948   uint this_trap_count = 0;
1949   if (update_total_trap_count) {
1950     uint idx = reason;
1951 #if INCLUDE_JVMCI
1952     if (is_osr) {
1953       idx += Reason_LIMIT;
1954     }
1955 #endif
1956     uint prior_trap_count = trap_mdo->trap_count(idx);
1957     this_trap_count  = trap_mdo->inc_trap_count(idx);
1958 
1959     // If the runtime cannot find a place to store trap history,
1960     // it is estimated based on the general condition of the method.
1961     // If the method has ever been recompiled, or has ever incurred
1962     // a trap with the present reason , then this BCI is assumed
1963     // (pessimistically) to be the culprit.
1964     maybe_prior_trap      = (prior_trap_count != 0);
1965     maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1966   }
1967   ProfileData* pdata = NULL;
1968 
1969 
1970   // For reasons which are recorded per bytecode, we check per-BCI data.
1971   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1972   assert(per_bc_reason != Reason_none || update_total_trap_count, "must be");
1973   if (per_bc_reason != Reason_none) {
1974     // Find the profile data for this BCI.  If there isn't one,
1975     // try to allocate one from the MDO's set of spares.
1976     // This will let us detect a repeated trap at this point.
1977     pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
1978 
1979     if (pdata != NULL) {
1980       if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
1981         if (LogCompilation && xtty != NULL) {
1982           ttyLocker ttyl;
1983           // no more room for speculative traps in this MDO
1984           xtty->elem("speculative_traps_oom");
1985         }
1986       }
1987       // Query the trap state of this profile datum.
1988       int tstate0 = pdata->trap_state();
1989       if (!trap_state_has_reason(tstate0, per_bc_reason))
1990         maybe_prior_trap = false;
1991       if (!trap_state_is_recompiled(tstate0))
1992         maybe_prior_recompile = false;
1993 
1994       // Update the trap state of this profile datum.
1995       int tstate1 = tstate0;
1996       // Record the reason.
1997       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1998       // Store the updated state on the MDO, for next time.
1999       if (tstate1 != tstate0)
2000         pdata->set_trap_state(tstate1);
2001     } else {
2002       if (LogCompilation && xtty != NULL) {
2003         ttyLocker ttyl;
2004         // Missing MDP?  Leave a small complaint in the log.
2005         xtty->elem("missing_mdp bci='%d'", trap_bci);
2006       }
2007     }
2008   }
2009 
2010   // Return results:
2011   ret_this_trap_count = this_trap_count;
2012   ret_maybe_prior_trap = maybe_prior_trap;
2013   ret_maybe_prior_recompile = maybe_prior_recompile;
2014   return pdata;
2015 }
2016 
2017 void
2018 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2019   ResourceMark rm;
2020   // Ignored outputs:
2021   uint ignore_this_trap_count;
2022   bool ignore_maybe_prior_trap;
2023   bool ignore_maybe_prior_recompile;
2024   assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
2025   // JVMCI uses the total counts to determine if deoptimizations are happening too frequently -> do not adjust total counts
2026   bool update_total_counts = JVMCI_ONLY(false) NOT_JVMCI(true);
2027   query_update_method_data(trap_mdo, trap_bci,
2028                            (DeoptReason)reason,
2029                            update_total_counts,
2030 #if INCLUDE_JVMCI
2031                            false,
2032 #endif
2033                            NULL,
2034                            ignore_this_trap_count,
2035                            ignore_maybe_prior_trap,
2036                            ignore_maybe_prior_recompile);
2037 }
2038 
2039 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request, jint exec_mode) {
2040   if (TraceDeoptimization) {
2041     tty->print("Uncommon trap ");
2042   }
2043   // Still in Java no safepoints
2044   {
2045     // This enters VM and may safepoint
2046     uncommon_trap_inner(thread, trap_request);
2047   }
2048   return fetch_unroll_info_helper(thread, exec_mode);
2049 }
2050 
2051 // Local derived constants.
2052 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2053 const int DS_REASON_MASK   = DataLayout::trap_mask >> 1;
2054 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2055 
2056 //---------------------------trap_state_reason---------------------------------
2057 Deoptimization::DeoptReason
2058 Deoptimization::trap_state_reason(int trap_state) {
2059   // This assert provides the link between the width of DataLayout::trap_bits
2060   // and the encoding of "recorded" reasons.  It ensures there are enough
2061   // bits to store all needed reasons in the per-BCI MDO profile.
2062   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2063   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2064   trap_state -= recompile_bit;
2065   if (trap_state == DS_REASON_MASK) {
2066     return Reason_many;
2067   } else {
2068     assert((int)Reason_none == 0, "state=0 => Reason_none");
2069     return (DeoptReason)trap_state;
2070   }
2071 }
2072 //-------------------------trap_state_has_reason-------------------------------
2073 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2074   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2075   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2076   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2077   trap_state -= recompile_bit;
2078   if (trap_state == DS_REASON_MASK) {
2079     return -1;  // true, unspecifically (bottom of state lattice)
2080   } else if (trap_state == reason) {
2081     return 1;   // true, definitely
2082   } else if (trap_state == 0) {
2083     return 0;   // false, definitely (top of state lattice)
2084   } else {
2085     return 0;   // false, definitely
2086   }
2087 }
2088 //-------------------------trap_state_add_reason-------------------------------
2089 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2090   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2091   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2092   trap_state -= recompile_bit;
2093   if (trap_state == DS_REASON_MASK) {
2094     return trap_state + recompile_bit;     // already at state lattice bottom
2095   } else if (trap_state == reason) {
2096     return trap_state + recompile_bit;     // the condition is already true
2097   } else if (trap_state == 0) {
2098     return reason + recompile_bit;          // no condition has yet been true
2099   } else {
2100     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
2101   }
2102 }
2103 //-----------------------trap_state_is_recompiled------------------------------
2104 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2105   return (trap_state & DS_RECOMPILE_BIT) != 0;
2106 }
2107 //-----------------------trap_state_set_recompiled-----------------------------
2108 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2109   if (z)  return trap_state |  DS_RECOMPILE_BIT;
2110   else    return trap_state & ~DS_RECOMPILE_BIT;
2111 }
2112 //---------------------------format_trap_state---------------------------------
2113 // This is used for debugging and diagnostics, including LogFile output.
2114 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2115                                               int trap_state) {
2116   assert(buflen > 0, "sanity");
2117   DeoptReason reason      = trap_state_reason(trap_state);
2118   bool        recomp_flag = trap_state_is_recompiled(trap_state);
2119   // Re-encode the state from its decoded components.
2120   int decoded_state = 0;
2121   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2122     decoded_state = trap_state_add_reason(decoded_state, reason);
2123   if (recomp_flag)
2124     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2125   // If the state re-encodes properly, format it symbolically.
2126   // Because this routine is used for debugging and diagnostics,
2127   // be robust even if the state is a strange value.
2128   size_t len;
2129   if (decoded_state != trap_state) {
2130     // Random buggy state that doesn't decode??
2131     len = jio_snprintf(buf, buflen, "#%d", trap_state);
2132   } else {
2133     len = jio_snprintf(buf, buflen, "%s%s",
2134                        trap_reason_name(reason),
2135                        recomp_flag ? " recompiled" : "");
2136   }
2137   return buf;
2138 }
2139 
2140 
2141 //--------------------------------statics--------------------------------------
2142 const char* Deoptimization::_trap_reason_name[] = {
2143   // Note:  Keep this in sync. with enum DeoptReason.
2144   "none",
2145   "null_check",
2146   "null_assert" JVMCI_ONLY("_or_unreached0"),
2147   "range_check",
2148   "class_check",
2149   "array_check",
2150   "intrinsic" JVMCI_ONLY("_or_type_checked_inlining"),
2151   "bimorphic" JVMCI_ONLY("_or_optimized_type_check"),
2152   "unloaded",
2153   "uninitialized",
2154   "unreached",
2155   "unhandled",
2156   "constraint",
2157   "div0_check",
2158   "age",
2159   "predicate",
2160   "loop_limit_check",
2161   "speculate_class_check",
2162   "speculate_null_check",
2163   "rtm_state_change",
2164   "unstable_if",
2165   "unstable_fused_if",
2166 #if INCLUDE_JVMCI
2167   "aliasing",
2168   "transfer_to_interpreter",
2169   "not_compiled_exception_handler",
2170   "unresolved",
2171   "jsr_mismatch",
2172 #endif
2173   "tenured"
2174 };
2175 const char* Deoptimization::_trap_action_name[] = {
2176   // Note:  Keep this in sync. with enum DeoptAction.
2177   "none",
2178   "maybe_recompile",
2179   "reinterpret",
2180   "make_not_entrant",
2181   "make_not_compilable"
2182 };
2183 
2184 const char* Deoptimization::trap_reason_name(int reason) {
2185   // Check that every reason has a name
2186   STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2187 
2188   if (reason == Reason_many)  return "many";
2189   if ((uint)reason < Reason_LIMIT)
2190     return _trap_reason_name[reason];
2191   static char buf[20];
2192   sprintf(buf, "reason%d", reason);
2193   return buf;
2194 }
2195 const char* Deoptimization::trap_action_name(int action) {
2196   // Check that every action has a name
2197   STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2198 
2199   if ((uint)action < Action_LIMIT)
2200     return _trap_action_name[action];
2201   static char buf[20];
2202   sprintf(buf, "action%d", action);
2203   return buf;
2204 }
2205 
2206 // This is used for debugging and diagnostics, including LogFile output.
2207 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2208                                                 int trap_request) {
2209   jint unloaded_class_index = trap_request_index(trap_request);
2210   const char* reason = trap_reason_name(trap_request_reason(trap_request));
2211   const char* action = trap_action_name(trap_request_action(trap_request));
2212 #if INCLUDE_JVMCI
2213   int debug_id = trap_request_debug_id(trap_request);
2214 #endif
2215   size_t len;
2216   if (unloaded_class_index < 0) {
2217     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'" JVMCI_ONLY(" debug_id='%d'"),
2218                        reason, action
2219 #if INCLUDE_JVMCI
2220                        ,debug_id
2221 #endif
2222                        );
2223   } else {
2224     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'" JVMCI_ONLY(" debug_id='%d'"),
2225                        reason, action, unloaded_class_index
2226 #if INCLUDE_JVMCI
2227                        ,debug_id
2228 #endif
2229                        );
2230   }
2231   return buf;
2232 }
2233 
2234 juint Deoptimization::_deoptimization_hist
2235         [Deoptimization::Reason_LIMIT]
2236     [1 + Deoptimization::Action_LIMIT]
2237         [Deoptimization::BC_CASE_LIMIT]
2238   = {0};
2239 
2240 enum {
2241   LSB_BITS = 8,
2242   LSB_MASK = right_n_bits(LSB_BITS)
2243 };
2244 
2245 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2246                                        Bytecodes::Code bc) {
2247   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2248   assert(action >= 0 && action < Action_LIMIT, "oob");
2249   _deoptimization_hist[Reason_none][0][0] += 1;  // total
2250   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
2251   juint* cases = _deoptimization_hist[reason][1+action];
2252   juint* bc_counter_addr = NULL;
2253   juint  bc_counter      = 0;
2254   // Look for an unused counter, or an exact match to this BC.
2255   if (bc != Bytecodes::_illegal) {
2256     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2257       juint* counter_addr = &cases[bc_case];
2258       juint  counter = *counter_addr;
2259       if ((counter == 0 && bc_counter_addr == NULL)
2260           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2261         // this counter is either free or is already devoted to this BC
2262         bc_counter_addr = counter_addr;
2263         bc_counter = counter | bc;
2264       }
2265     }
2266   }
2267   if (bc_counter_addr == NULL) {
2268     // Overflow, or no given bytecode.
2269     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
2270     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
2271   }
2272   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2273 }
2274 
2275 jint Deoptimization::total_deoptimization_count() {
2276   return _deoptimization_hist[Reason_none][0][0];
2277 }
2278 
2279 jint Deoptimization::deoptimization_count(DeoptReason reason) {
2280   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2281   return _deoptimization_hist[reason][0][0];
2282 }
2283 
2284 void Deoptimization::print_statistics() {
2285   juint total = total_deoptimization_count();
2286   juint account = total;
2287   if (total != 0) {
2288     ttyLocker ttyl;
2289     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
2290     tty->print_cr("Deoptimization traps recorded:");
2291     #define PRINT_STAT_LINE(name, r) \
2292       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2293     PRINT_STAT_LINE("total", total);
2294     // For each non-zero entry in the histogram, print the reason,
2295     // the action, and (if specifically known) the type of bytecode.
2296     for (int reason = 0; reason < Reason_LIMIT; reason++) {
2297       for (int action = 0; action < Action_LIMIT; action++) {
2298         juint* cases = _deoptimization_hist[reason][1+action];
2299         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2300           juint counter = cases[bc_case];
2301           if (counter != 0) {
2302             char name[1*K];
2303             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2304             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
2305               bc = Bytecodes::_illegal;
2306             sprintf(name, "%s/%s/%s",
2307                     trap_reason_name(reason),
2308                     trap_action_name(action),
2309                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2310             juint r = counter >> LSB_BITS;
2311             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2312             account -= r;
2313           }
2314         }
2315       }
2316     }
2317     if (account != 0) {
2318       PRINT_STAT_LINE("unaccounted", account);
2319     }
2320     #undef PRINT_STAT_LINE
2321     if (xtty != NULL)  xtty->tail("statistics");
2322   }
2323 }
2324 #else // COMPILER2 || SHARK || INCLUDE_JVMCI
2325 
2326 
2327 // Stubs for C1 only system.
2328 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2329   return false;
2330 }
2331 
2332 const char* Deoptimization::trap_reason_name(int reason) {
2333   return "unknown";
2334 }
2335 
2336 void Deoptimization::print_statistics() {
2337   // no output
2338 }
2339 
2340 void
2341 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2342   // no udpate
2343 }
2344 
2345 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2346   return 0;
2347 }
2348 
2349 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2350                                        Bytecodes::Code bc) {
2351   // no update
2352 }
2353 
2354 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2355                                               int trap_state) {
2356   jio_snprintf(buf, buflen, "#%d", trap_state);
2357   return buf;
2358 }
2359 
2360 #endif // COMPILER2 || SHARK || INCLUDE_JVMCI