1 /*
   2  * Copyright (c) 1999, 2022, 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 "asm/codeBuffer.hpp"
  27 #include "c1/c1_CodeStubs.hpp"
  28 #include "c1/c1_Defs.hpp"
  29 #include "c1/c1_FrameMap.hpp"
  30 #include "c1/c1_LIRAssembler.hpp"
  31 #include "c1/c1_MacroAssembler.hpp"
  32 #include "c1/c1_Runtime1.hpp"
  33 #include "classfile/javaClasses.inline.hpp"
  34 #include "classfile/vmClasses.hpp"
  35 #include "classfile/vmSymbols.hpp"
  36 #include "code/codeBlob.hpp"
  37 #include "code/compiledIC.hpp"
  38 #include "code/pcDesc.hpp"
  39 #include "code/scopeDesc.hpp"
  40 #include "code/vtableStubs.hpp"
  41 #include "compiler/compilationPolicy.hpp"
  42 #include "compiler/disassembler.hpp"
  43 #include "compiler/oopMap.hpp"
  44 #include "gc/shared/barrierSet.hpp"
  45 #include "gc/shared/c1/barrierSetC1.hpp"
  46 #include "gc/shared/collectedHeap.hpp"
  47 #include "interpreter/bytecode.hpp"
  48 #include "interpreter/interpreter.hpp"
  49 #include "jfr/support/jfrIntrinsics.hpp"
  50 #include "logging/log.hpp"
  51 #include "memory/allocation.inline.hpp"
  52 #include "memory/oopFactory.hpp"
  53 #include "memory/resourceArea.hpp"
  54 #include "memory/universe.hpp"
  55 #include "oops/access.inline.hpp"
  56 #include "oops/klass.inline.hpp"
  57 #include "oops/objArrayOop.inline.hpp"
  58 #include "oops/objArrayKlass.hpp"
  59 #include "oops/oop.inline.hpp"
  60 #include "prims/jvmtiExport.hpp"
  61 #include "runtime/atomic.hpp"
  62 #include "runtime/fieldDescriptor.inline.hpp"
  63 #include "runtime/frame.inline.hpp"
  64 #include "runtime/handles.inline.hpp"
  65 #include "runtime/interfaceSupport.inline.hpp"
  66 #include "runtime/javaCalls.hpp"
  67 #include "runtime/sharedRuntime.hpp"
  68 #include "runtime/stackWatermarkSet.hpp"
  69 #include "runtime/stubRoutines.hpp"
  70 #include "runtime/threadCritical.hpp"
  71 #include "runtime/vframe.inline.hpp"
  72 #include "runtime/vframeArray.hpp"
  73 #include "runtime/vm_version.hpp"
  74 #include "utilities/copy.hpp"
  75 #include "utilities/events.hpp"
  76 
  77 
  78 // Implementation of StubAssembler
  79 
  80 StubAssembler::StubAssembler(CodeBuffer* code, const char * name, int stub_id) : C1_MacroAssembler(code) {
  81   _name = name;
  82   _must_gc_arguments = false;
  83   _frame_size = no_frame_size;
  84   _num_rt_args = 0;
  85   _stub_id = stub_id;
  86 }
  87 
  88 
  89 void StubAssembler::set_info(const char* name, bool must_gc_arguments) {
  90   _name = name;
  91   _must_gc_arguments = must_gc_arguments;
  92 }
  93 
  94 
  95 void StubAssembler::set_frame_size(int size) {
  96   if (_frame_size == no_frame_size) {
  97     _frame_size = size;
  98   }
  99   assert(_frame_size == size, "can't change the frame size");
 100 }
 101 
 102 
 103 void StubAssembler::set_num_rt_args(int args) {
 104   if (_num_rt_args == 0) {
 105     _num_rt_args = args;
 106   }
 107   assert(_num_rt_args == args, "can't change the number of args");
 108 }
 109 
 110 // Implementation of Runtime1
 111 
 112 CodeBlob* Runtime1::_blobs[Runtime1::number_of_ids];
 113 const char *Runtime1::_blob_names[] = {
 114   RUNTIME1_STUBS(STUB_NAME, LAST_STUB_NAME)
 115 };
 116 
 117 #ifndef PRODUCT
 118 // statistics
 119 int Runtime1::_generic_arraycopystub_cnt = 0;
 120 int Runtime1::_arraycopy_slowcase_cnt = 0;
 121 int Runtime1::_arraycopy_checkcast_cnt = 0;
 122 int Runtime1::_arraycopy_checkcast_attempt_cnt = 0;
 123 int Runtime1::_new_type_array_slowcase_cnt = 0;
 124 int Runtime1::_new_object_array_slowcase_cnt = 0;
 125 int Runtime1::_new_instance_slowcase_cnt = 0;
 126 int Runtime1::_new_multi_array_slowcase_cnt = 0;
 127 int Runtime1::_monitorenter_slowcase_cnt = 0;
 128 int Runtime1::_monitorexit_slowcase_cnt = 0;
 129 int Runtime1::_patch_code_slowcase_cnt = 0;
 130 int Runtime1::_throw_range_check_exception_count = 0;
 131 int Runtime1::_throw_index_exception_count = 0;
 132 int Runtime1::_throw_div0_exception_count = 0;
 133 int Runtime1::_throw_null_pointer_exception_count = 0;
 134 int Runtime1::_throw_class_cast_exception_count = 0;
 135 int Runtime1::_throw_incompatible_class_change_error_count = 0;
 136 int Runtime1::_throw_count = 0;
 137 
 138 static int _byte_arraycopy_stub_cnt = 0;
 139 static int _short_arraycopy_stub_cnt = 0;
 140 static int _int_arraycopy_stub_cnt = 0;
 141 static int _long_arraycopy_stub_cnt = 0;
 142 static int _oop_arraycopy_stub_cnt = 0;
 143 
 144 address Runtime1::arraycopy_count_address(BasicType type) {
 145   switch (type) {
 146   case T_BOOLEAN:
 147   case T_BYTE:   return (address)&_byte_arraycopy_stub_cnt;
 148   case T_CHAR:
 149   case T_SHORT:  return (address)&_short_arraycopy_stub_cnt;
 150   case T_FLOAT:
 151   case T_INT:    return (address)&_int_arraycopy_stub_cnt;
 152   case T_DOUBLE:
 153   case T_LONG:   return (address)&_long_arraycopy_stub_cnt;
 154   case T_ARRAY:
 155   case T_OBJECT: return (address)&_oop_arraycopy_stub_cnt;
 156   default:
 157     ShouldNotReachHere();
 158     return NULL;
 159   }
 160 }
 161 
 162 
 163 #endif
 164 
 165 // Simple helper to see if the caller of a runtime stub which
 166 // entered the VM has been deoptimized
 167 
 168 static bool caller_is_deopted(JavaThread* current) {
 169   RegisterMap reg_map(current,
 170                       RegisterMap::UpdateMap::skip,
 171                       RegisterMap::ProcessFrames::include,
 172                       RegisterMap::WalkContinuation::skip);
 173   frame runtime_frame = current->last_frame();
 174   frame caller_frame = runtime_frame.sender(&reg_map);
 175   assert(caller_frame.is_compiled_frame(), "must be compiled");
 176   return caller_frame.is_deoptimized_frame();
 177 }
 178 
 179 // Stress deoptimization
 180 static void deopt_caller(JavaThread* current) {
 181   if (!caller_is_deopted(current)) {
 182     RegisterMap reg_map(current,
 183                         RegisterMap::UpdateMap::skip,
 184                         RegisterMap::ProcessFrames::include,
 185                         RegisterMap::WalkContinuation::skip);
 186     frame runtime_frame = current->last_frame();
 187     frame caller_frame = runtime_frame.sender(&reg_map);
 188     Deoptimization::deoptimize_frame(current, caller_frame.id());
 189     assert(caller_is_deopted(current), "Must be deoptimized");
 190   }
 191 }
 192 
 193 class StubIDStubAssemblerCodeGenClosure: public StubAssemblerCodeGenClosure {
 194  private:
 195   Runtime1::StubID _id;
 196  public:
 197   StubIDStubAssemblerCodeGenClosure(Runtime1::StubID id) : _id(id) {}
 198   virtual OopMapSet* generate_code(StubAssembler* sasm) {
 199     return Runtime1::generate_code_for(_id, sasm);
 200   }
 201 };
 202 
 203 CodeBlob* Runtime1::generate_blob(BufferBlob* buffer_blob, int stub_id, const char* name, bool expect_oop_map, StubAssemblerCodeGenClosure* cl) {
 204   ResourceMark rm;
 205   // create code buffer for code storage
 206   CodeBuffer code(buffer_blob);
 207 
 208   OopMapSet* oop_maps;
 209   int frame_size;
 210   bool must_gc_arguments;
 211 
 212   Compilation::setup_code_buffer(&code, 0);
 213 
 214   // create assembler for code generation
 215   StubAssembler* sasm = new StubAssembler(&code, name, stub_id);
 216   // generate code for runtime stub
 217   oop_maps = cl->generate_code(sasm);
 218   assert(oop_maps == NULL || sasm->frame_size() != no_frame_size,
 219          "if stub has an oop map it must have a valid frame size");
 220   assert(!expect_oop_map || oop_maps != NULL, "must have an oopmap");
 221 
 222   // align so printing shows nop's instead of random code at the end (SimpleStubs are aligned)
 223   sasm->align(BytesPerWord);
 224   // make sure all code is in code buffer
 225   sasm->flush();
 226 
 227   frame_size = sasm->frame_size();
 228   must_gc_arguments = sasm->must_gc_arguments();
 229   // create blob - distinguish a few special cases
 230   CodeBlob* blob = RuntimeStub::new_runtime_stub(name,
 231                                                  &code,
 232                                                  CodeOffsets::frame_never_safe,
 233                                                  frame_size,
 234                                                  oop_maps,
 235                                                  must_gc_arguments);
 236   assert(blob != NULL, "blob must exist");
 237   return blob;
 238 }
 239 
 240 void Runtime1::generate_blob_for(BufferBlob* buffer_blob, StubID id) {
 241   assert(0 <= id && id < number_of_ids, "illegal stub id");
 242   bool expect_oop_map = true;
 243 #ifdef ASSERT
 244   // Make sure that stubs that need oopmaps have them
 245   switch (id) {
 246     // These stubs don't need to have an oopmap
 247   case load_klass_id:
 248   case dtrace_object_alloc_id:
 249   case slow_subtype_check_id:
 250   case fpu2long_stub_id:
 251   case unwind_exception_id:
 252   case counter_overflow_id:
 253     expect_oop_map = false;
 254     break;
 255   default:
 256     break;
 257   }
 258 #endif
 259   StubIDStubAssemblerCodeGenClosure cl(id);
 260   CodeBlob* blob = generate_blob(buffer_blob, id, name_for(id), expect_oop_map, &cl);
 261   // install blob
 262   _blobs[id] = blob;
 263 }
 264 
 265 void Runtime1::initialize(BufferBlob* blob) {
 266   // platform-dependent initialization
 267   initialize_pd();
 268   // generate stubs
 269   for (int id = 0; id < number_of_ids; id++) generate_blob_for(blob, (StubID)id);
 270   // printing
 271 #ifndef PRODUCT
 272   if (PrintSimpleStubs) {
 273     ResourceMark rm;
 274     for (int id = 0; id < number_of_ids; id++) {
 275       _blobs[id]->print();
 276       if (_blobs[id]->oop_maps() != NULL) {
 277         _blobs[id]->oop_maps()->print();
 278       }
 279     }
 280   }
 281 #endif
 282   BarrierSetC1* bs = BarrierSet::barrier_set()->barrier_set_c1();
 283   bs->generate_c1_runtime_stubs(blob);
 284 }
 285 
 286 CodeBlob* Runtime1::blob_for(StubID id) {
 287   assert(0 <= id && id < number_of_ids, "illegal stub id");
 288   return _blobs[id];
 289 }
 290 
 291 
 292 const char* Runtime1::name_for(StubID id) {
 293   assert(0 <= id && id < number_of_ids, "illegal stub id");
 294   return _blob_names[id];
 295 }
 296 
 297 const char* Runtime1::name_for_address(address entry) {
 298   for (int id = 0; id < number_of_ids; id++) {
 299     if (entry == entry_for((StubID)id)) return name_for((StubID)id);
 300   }
 301 
 302 #define FUNCTION_CASE(a, f) \
 303   if ((intptr_t)a == CAST_FROM_FN_PTR(intptr_t, f))  return #f
 304 
 305   FUNCTION_CASE(entry, os::javaTimeMillis);
 306   FUNCTION_CASE(entry, os::javaTimeNanos);
 307   FUNCTION_CASE(entry, SharedRuntime::OSR_migration_end);
 308   FUNCTION_CASE(entry, SharedRuntime::d2f);
 309   FUNCTION_CASE(entry, SharedRuntime::d2i);
 310   FUNCTION_CASE(entry, SharedRuntime::d2l);
 311   FUNCTION_CASE(entry, SharedRuntime::dcos);
 312   FUNCTION_CASE(entry, SharedRuntime::dexp);
 313   FUNCTION_CASE(entry, SharedRuntime::dlog);
 314   FUNCTION_CASE(entry, SharedRuntime::dlog10);
 315   FUNCTION_CASE(entry, SharedRuntime::dpow);
 316   FUNCTION_CASE(entry, SharedRuntime::drem);
 317   FUNCTION_CASE(entry, SharedRuntime::dsin);
 318   FUNCTION_CASE(entry, SharedRuntime::dtan);
 319   FUNCTION_CASE(entry, SharedRuntime::f2i);
 320   FUNCTION_CASE(entry, SharedRuntime::f2l);
 321   FUNCTION_CASE(entry, SharedRuntime::frem);
 322   FUNCTION_CASE(entry, SharedRuntime::l2d);
 323   FUNCTION_CASE(entry, SharedRuntime::l2f);
 324   FUNCTION_CASE(entry, SharedRuntime::ldiv);
 325   FUNCTION_CASE(entry, SharedRuntime::lmul);
 326   FUNCTION_CASE(entry, SharedRuntime::lrem);
 327   FUNCTION_CASE(entry, SharedRuntime::lrem);
 328   FUNCTION_CASE(entry, SharedRuntime::dtrace_method_entry);
 329   FUNCTION_CASE(entry, SharedRuntime::dtrace_method_exit);
 330   FUNCTION_CASE(entry, is_instance_of);
 331   FUNCTION_CASE(entry, trace_block_entry);
 332 #ifdef JFR_HAVE_INTRINSICS
 333   FUNCTION_CASE(entry, JfrTime::time_function());
 334 #endif
 335   FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32());
 336   FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32C());
 337   FUNCTION_CASE(entry, StubRoutines::vectorizedMismatch());
 338   FUNCTION_CASE(entry, StubRoutines::dexp());
 339   FUNCTION_CASE(entry, StubRoutines::dlog());
 340   FUNCTION_CASE(entry, StubRoutines::dlog10());
 341   FUNCTION_CASE(entry, StubRoutines::dpow());
 342   FUNCTION_CASE(entry, StubRoutines::dsin());
 343   FUNCTION_CASE(entry, StubRoutines::dcos());
 344   FUNCTION_CASE(entry, StubRoutines::dtan());
 345   FUNCTION_CASE(entry, StubRoutines::cont_doYield());
 346 
 347 #undef FUNCTION_CASE
 348 
 349   // Soft float adds more runtime names.
 350   return pd_name_for_address(entry);
 351 }
 352 
 353 
 354 JRT_ENTRY(void, Runtime1::new_instance(JavaThread* current, Klass* klass))
 355 #ifndef PRODUCT
 356   if (PrintC1Statistics) {
 357     _new_instance_slowcase_cnt++;
 358   }
 359 #endif
 360   assert(klass->is_klass(), "not a class");
 361   Handle holder(current, klass->klass_holder()); // keep the klass alive
 362   InstanceKlass* h = InstanceKlass::cast(klass);
 363   h->check_valid_for_instantiation(true, CHECK);
 364   // make sure klass is initialized
 365   h->initialize(CHECK);
 366   // allocate instance and return via TLS
 367   oop obj = h->allocate_instance(CHECK);
 368   current->set_vm_result(obj);
 369 JRT_END
 370 
 371 
 372 JRT_ENTRY(void, Runtime1::new_type_array(JavaThread* current, Klass* klass, jint length))
 373 #ifndef PRODUCT
 374   if (PrintC1Statistics) {
 375     _new_type_array_slowcase_cnt++;
 376   }
 377 #endif
 378   // Note: no handle for klass needed since they are not used
 379   //       anymore after new_typeArray() and no GC can happen before.
 380   //       (This may have to change if this code changes!)
 381   assert(klass->is_klass(), "not a class");
 382   BasicType elt_type = TypeArrayKlass::cast(klass)->element_type();
 383   oop obj = oopFactory::new_typeArray(elt_type, length, CHECK);
 384   current->set_vm_result(obj);
 385   // This is pretty rare but this runtime patch is stressful to deoptimization
 386   // if we deoptimize here so force a deopt to stress the path.
 387   if (DeoptimizeALot) {
 388     deopt_caller(current);
 389   }
 390 
 391 JRT_END
 392 
 393 
 394 JRT_ENTRY(void, Runtime1::new_object_array(JavaThread* current, Klass* array_klass, jint length))
 395 #ifndef PRODUCT
 396   if (PrintC1Statistics) {
 397     _new_object_array_slowcase_cnt++;
 398   }
 399 #endif
 400   // Note: no handle for klass needed since they are not used
 401   //       anymore after new_objArray() and no GC can happen before.
 402   //       (This may have to change if this code changes!)
 403   assert(array_klass->is_klass(), "not a class");
 404   Handle holder(current, array_klass->klass_holder()); // keep the klass alive
 405   Klass* elem_klass = ObjArrayKlass::cast(array_klass)->element_klass();
 406   objArrayOop obj = oopFactory::new_objArray(elem_klass, length, CHECK);
 407   current->set_vm_result(obj);
 408   // This is pretty rare but this runtime patch is stressful to deoptimization
 409   // if we deoptimize here so force a deopt to stress the path.
 410   if (DeoptimizeALot) {
 411     deopt_caller(current);
 412   }
 413 JRT_END
 414 
 415 
 416 JRT_ENTRY(void, Runtime1::new_multi_array(JavaThread* current, Klass* klass, int rank, jint* dims))
 417 #ifndef PRODUCT
 418   if (PrintC1Statistics) {
 419     _new_multi_array_slowcase_cnt++;
 420   }
 421 #endif
 422   assert(klass->is_klass(), "not a class");
 423   assert(rank >= 1, "rank must be nonzero");
 424   Handle holder(current, klass->klass_holder()); // keep the klass alive
 425   oop obj = ArrayKlass::cast(klass)->multi_allocate(rank, dims, CHECK);
 426   current->set_vm_result(obj);
 427 JRT_END
 428 
 429 
 430 JRT_ENTRY(void, Runtime1::unimplemented_entry(JavaThread* current, StubID id))
 431   tty->print_cr("Runtime1::entry_for(%d) returned unimplemented entry point", id);
 432 JRT_END
 433 
 434 
 435 JRT_ENTRY(void, Runtime1::throw_array_store_exception(JavaThread* current, oopDesc* obj))
 436   ResourceMark rm(current);
 437   const char* klass_name = obj->klass()->external_name();
 438   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayStoreException(), klass_name);
 439 JRT_END
 440 
 441 
 442 // counter_overflow() is called from within C1-compiled methods. The enclosing method is the method
 443 // associated with the top activation record. The inlinee (that is possibly included in the enclosing
 444 // method) method is passed as an argument. In order to do that it is embedded in the code as
 445 // a constant.
 446 static nmethod* counter_overflow_helper(JavaThread* current, int branch_bci, Method* m) {
 447   nmethod* osr_nm = NULL;
 448   methodHandle method(current, m);
 449 
 450   RegisterMap map(current,
 451                   RegisterMap::UpdateMap::skip,
 452                   RegisterMap::ProcessFrames::include,
 453                   RegisterMap::WalkContinuation::skip);
 454   frame fr =  current->last_frame().sender(&map);
 455   nmethod* nm = (nmethod*) fr.cb();
 456   assert(nm!= NULL && nm->is_nmethod(), "Sanity check");
 457   methodHandle enclosing_method(current, nm->method());
 458 
 459   CompLevel level = (CompLevel)nm->comp_level();
 460   int bci = InvocationEntryBci;
 461   if (branch_bci != InvocationEntryBci) {
 462     // Compute destination bci
 463     address pc = method()->code_base() + branch_bci;
 464     Bytecodes::Code branch = Bytecodes::code_at(method(), pc);
 465     int offset = 0;
 466     switch (branch) {
 467       case Bytecodes::_if_icmplt: case Bytecodes::_iflt:
 468       case Bytecodes::_if_icmpgt: case Bytecodes::_ifgt:
 469       case Bytecodes::_if_icmple: case Bytecodes::_ifle:
 470       case Bytecodes::_if_icmpge: case Bytecodes::_ifge:
 471       case Bytecodes::_if_icmpeq: case Bytecodes::_if_acmpeq: case Bytecodes::_ifeq:
 472       case Bytecodes::_if_icmpne: case Bytecodes::_if_acmpne: case Bytecodes::_ifne:
 473       case Bytecodes::_ifnull: case Bytecodes::_ifnonnull: case Bytecodes::_goto:
 474         offset = (int16_t)Bytes::get_Java_u2(pc + 1);
 475         break;
 476       case Bytecodes::_goto_w:
 477         offset = Bytes::get_Java_u4(pc + 1);
 478         break;
 479       default: ;
 480     }
 481     bci = branch_bci + offset;
 482   }
 483   osr_nm = CompilationPolicy::event(enclosing_method, method, branch_bci, bci, level, nm, current);
 484   return osr_nm;
 485 }
 486 
 487 JRT_BLOCK_ENTRY(address, Runtime1::counter_overflow(JavaThread* current, int bci, Method* method))
 488   nmethod* osr_nm;
 489   JRT_BLOCK
 490     osr_nm = counter_overflow_helper(current, bci, method);
 491     if (osr_nm != NULL) {
 492       RegisterMap map(current,
 493                       RegisterMap::UpdateMap::skip,
 494                       RegisterMap::ProcessFrames::include,
 495                       RegisterMap::WalkContinuation::skip);
 496       frame fr =  current->last_frame().sender(&map);
 497       Deoptimization::deoptimize_frame(current, fr.id());
 498     }
 499   JRT_BLOCK_END
 500   return NULL;
 501 JRT_END
 502 
 503 extern void vm_exit(int code);
 504 
 505 // Enter this method from compiled code handler below. This is where we transition
 506 // to VM mode. This is done as a helper routine so that the method called directly
 507 // from compiled code does not have to transition to VM. This allows the entry
 508 // method to see if the nmethod that we have just looked up a handler for has
 509 // been deoptimized while we were in the vm. This simplifies the assembly code
 510 // cpu directories.
 511 //
 512 // We are entering here from exception stub (via the entry method below)
 513 // If there is a compiled exception handler in this method, we will continue there;
 514 // otherwise we will unwind the stack and continue at the caller of top frame method
 515 // Note: we enter in Java using a special JRT wrapper. This wrapper allows us to
 516 // control the area where we can allow a safepoint. After we exit the safepoint area we can
 517 // check to see if the handler we are going to return is now in a nmethod that has
 518 // been deoptimized. If that is the case we return the deopt blob
 519 // unpack_with_exception entry instead. This makes life for the exception blob easier
 520 // because making that same check and diverting is painful from assembly language.
 521 JRT_ENTRY_NO_ASYNC(static address, exception_handler_for_pc_helper(JavaThread* current, oopDesc* ex, address pc, nmethod*& nm))
 522   // Reset method handle flag.
 523   current->set_is_method_handle_return(false);
 524 
 525   Handle exception(current, ex);
 526 
 527   // This function is called when we are about to throw an exception. Therefore,
 528   // we have to poll the stack watermark barrier to make sure that not yet safe
 529   // stack frames are made safe before returning into them.
 530   if (current->last_frame().cb() == Runtime1::blob_for(Runtime1::handle_exception_from_callee_id)) {
 531     // The Runtime1::handle_exception_from_callee_id handler is invoked after the
 532     // frame has been unwound. It instead builds its own stub frame, to call the
 533     // runtime. But the throwing frame has already been unwound here.
 534     StackWatermarkSet::after_unwind(current);
 535   }
 536 
 537   nm = CodeCache::find_nmethod(pc);
 538   assert(nm != NULL, "this is not an nmethod");
 539   // Adjust the pc as needed/
 540   if (nm->is_deopt_pc(pc)) {
 541     RegisterMap map(current,
 542                     RegisterMap::UpdateMap::skip,
 543                     RegisterMap::ProcessFrames::include,
 544                     RegisterMap::WalkContinuation::skip);
 545     frame exception_frame = current->last_frame().sender(&map);
 546     // if the frame isn't deopted then pc must not correspond to the caller of last_frame
 547     assert(exception_frame.is_deoptimized_frame(), "must be deopted");
 548     pc = exception_frame.pc();
 549   }
 550   assert(exception.not_null(), "NULL exceptions should be handled by throw_exception");
 551   // Check that exception is a subclass of Throwable
 552   assert(exception->is_a(vmClasses::Throwable_klass()),
 553          "Exception not subclass of Throwable");
 554 
 555   // debugging support
 556   // tracing
 557   if (log_is_enabled(Info, exceptions)) {
 558     ResourceMark rm;
 559     stringStream tempst;
 560     assert(nm->method() != NULL, "Unexpected NULL method()");
 561     tempst.print("C1 compiled method <%s>\n"
 562                  " at PC" INTPTR_FORMAT " for thread " INTPTR_FORMAT,
 563                  nm->method()->print_value_string(), p2i(pc), p2i(current));
 564     Exceptions::log_exception(exception, tempst.as_string());
 565   }
 566   // for AbortVMOnException flag
 567   Exceptions::debug_check_abort(exception);
 568 
 569   // Check the stack guard pages and re-enable them if necessary and there is
 570   // enough space on the stack to do so.  Use fast exceptions only if the guard
 571   // pages are enabled.
 572   bool guard_pages_enabled = current->stack_overflow_state()->reguard_stack_if_needed();
 573 
 574   if (JvmtiExport::can_post_on_exceptions()) {
 575     // To ensure correct notification of exception catches and throws
 576     // we have to deoptimize here.  If we attempted to notify the
 577     // catches and throws during this exception lookup it's possible
 578     // we could deoptimize on the way out of the VM and end back in
 579     // the interpreter at the throw site.  This would result in double
 580     // notifications since the interpreter would also notify about
 581     // these same catches and throws as it unwound the frame.
 582 
 583     RegisterMap reg_map(current,
 584                         RegisterMap::UpdateMap::include,
 585                         RegisterMap::ProcessFrames::include,
 586                         RegisterMap::WalkContinuation::skip);
 587     frame stub_frame = current->last_frame();
 588     frame caller_frame = stub_frame.sender(&reg_map);
 589 
 590     // We don't really want to deoptimize the nmethod itself since we
 591     // can actually continue in the exception handler ourselves but I
 592     // don't see an easy way to have the desired effect.
 593     Deoptimization::deoptimize_frame(current, caller_frame.id());
 594     assert(caller_is_deopted(current), "Must be deoptimized");
 595 
 596     return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
 597   }
 598 
 599   // ExceptionCache is used only for exceptions at call sites and not for implicit exceptions
 600   if (guard_pages_enabled) {
 601     address fast_continuation = nm->handler_for_exception_and_pc(exception, pc);
 602     if (fast_continuation != NULL) {
 603       // Set flag if return address is a method handle call site.
 604       current->set_is_method_handle_return(nm->is_method_handle_return(pc));
 605       return fast_continuation;
 606     }
 607   }
 608 
 609   // If the stack guard pages are enabled, check whether there is a handler in
 610   // the current method.  Otherwise (guard pages disabled), force an unwind and
 611   // skip the exception cache update (i.e., just leave continuation==NULL).
 612   address continuation = NULL;
 613   if (guard_pages_enabled) {
 614 
 615     // New exception handling mechanism can support inlined methods
 616     // with exception handlers since the mappings are from PC to PC
 617 
 618     // Clear out the exception oop and pc since looking up an
 619     // exception handler can cause class loading, which might throw an
 620     // exception and those fields are expected to be clear during
 621     // normal bytecode execution.
 622     current->clear_exception_oop_and_pc();
 623 
 624     bool recursive_exception = false;
 625     continuation = SharedRuntime::compute_compiled_exc_handler(nm, pc, exception, false, false, recursive_exception);
 626     // If an exception was thrown during exception dispatch, the exception oop may have changed
 627     current->set_exception_oop(exception());
 628     current->set_exception_pc(pc);
 629 
 630     // the exception cache is used only by non-implicit exceptions
 631     // Update the exception cache only when there didn't happen
 632     // another exception during the computation of the compiled
 633     // exception handler. Checking for exception oop equality is not
 634     // sufficient because some exceptions are pre-allocated and reused.
 635     if (continuation != NULL && !recursive_exception) {
 636       nm->add_handler_for_exception_and_pc(exception, pc, continuation);
 637     }
 638   }
 639 
 640   current->set_vm_result(exception());
 641   // Set flag if return address is a method handle call site.
 642   current->set_is_method_handle_return(nm->is_method_handle_return(pc));
 643 
 644   if (log_is_enabled(Info, exceptions)) {
 645     ResourceMark rm;
 646     log_info(exceptions)("Thread " PTR_FORMAT " continuing at PC " PTR_FORMAT
 647                          " for exception thrown at PC " PTR_FORMAT,
 648                          p2i(current), p2i(continuation), p2i(pc));
 649   }
 650 
 651   return continuation;
 652 JRT_END
 653 
 654 // Enter this method from compiled code only if there is a Java exception handler
 655 // in the method handling the exception.
 656 // We are entering here from exception stub. We don't do a normal VM transition here.
 657 // We do it in a helper. This is so we can check to see if the nmethod we have just
 658 // searched for an exception handler has been deoptimized in the meantime.
 659 address Runtime1::exception_handler_for_pc(JavaThread* current) {
 660   oop exception = current->exception_oop();
 661   address pc = current->exception_pc();
 662   // Still in Java mode
 663   DEBUG_ONLY(NoHandleMark nhm);
 664   nmethod* nm = NULL;
 665   address continuation = NULL;
 666   {
 667     // Enter VM mode by calling the helper
 668     ResetNoHandleMark rnhm;
 669     continuation = exception_handler_for_pc_helper(current, exception, pc, nm);
 670   }
 671   // Back in JAVA, use no oops DON'T safepoint
 672 
 673   // Now check to see if the nmethod we were called from is now deoptimized.
 674   // If so we must return to the deopt blob and deoptimize the nmethod
 675   if (nm != NULL && caller_is_deopted(current)) {
 676     continuation = SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
 677   }
 678 
 679   assert(continuation != NULL, "no handler found");
 680   return continuation;
 681 }
 682 
 683 
 684 JRT_ENTRY(void, Runtime1::throw_range_check_exception(JavaThread* current, int index, arrayOopDesc* a))
 685 #ifndef PRODUCT
 686   if (PrintC1Statistics) {
 687     _throw_range_check_exception_count++;
 688   }
 689 #endif
 690   const int len = 35;
 691   assert(len < strlen("Index %d out of bounds for length %d"), "Must allocate more space for message.");
 692   char message[2 * jintAsStringSize + len];
 693   sprintf(message, "Index %d out of bounds for length %d", index, a->length());
 694   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), message);
 695 JRT_END
 696 
 697 
 698 JRT_ENTRY(void, Runtime1::throw_index_exception(JavaThread* current, int index))
 699 #ifndef PRODUCT
 700   if (PrintC1Statistics) {
 701     _throw_index_exception_count++;
 702   }
 703 #endif
 704   char message[16];
 705   sprintf(message, "%d", index);
 706   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IndexOutOfBoundsException(), message);
 707 JRT_END
 708 
 709 
 710 JRT_ENTRY(void, Runtime1::throw_div0_exception(JavaThread* current))
 711 #ifndef PRODUCT
 712   if (PrintC1Statistics) {
 713     _throw_div0_exception_count++;
 714   }
 715 #endif
 716   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArithmeticException(), "/ by zero");
 717 JRT_END
 718 
 719 
 720 JRT_ENTRY(void, Runtime1::throw_null_pointer_exception(JavaThread* current))
 721 #ifndef PRODUCT
 722   if (PrintC1Statistics) {
 723     _throw_null_pointer_exception_count++;
 724   }
 725 #endif
 726   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_NullPointerException());
 727 JRT_END
 728 
 729 
 730 JRT_ENTRY(void, Runtime1::throw_class_cast_exception(JavaThread* current, oopDesc* object))
 731 #ifndef PRODUCT
 732   if (PrintC1Statistics) {
 733     _throw_class_cast_exception_count++;
 734   }
 735 #endif
 736   ResourceMark rm(current);
 737   char* message = SharedRuntime::generate_class_cast_message(current, object->klass());
 738   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ClassCastException(), message);
 739 JRT_END
 740 
 741 
 742 JRT_ENTRY(void, Runtime1::throw_incompatible_class_change_error(JavaThread* current))
 743 #ifndef PRODUCT
 744   if (PrintC1Statistics) {
 745     _throw_incompatible_class_change_error_count++;
 746   }
 747 #endif
 748   ResourceMark rm(current);
 749   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IncompatibleClassChangeError());
 750 JRT_END
 751 
 752 
 753 JRT_BLOCK_ENTRY(void, Runtime1::monitorenter(JavaThread* current, oopDesc* obj, BasicObjectLock* lock))
 754 #ifndef PRODUCT
 755   if (PrintC1Statistics) {
 756     _monitorenter_slowcase_cnt++;
 757   }
 758 #endif
 759   if (UseHeavyMonitors) {
 760     lock->set_obj(obj);
 761   }
 762   assert(obj == lock->obj(), "must match");
 763   SharedRuntime::monitor_enter_helper(obj, lock->lock(), current);
 764 JRT_END
 765 
 766 
 767 JRT_LEAF(void, Runtime1::monitorexit(JavaThread* current, BasicObjectLock* lock))
 768 #ifndef PRODUCT
 769   if (PrintC1Statistics) {
 770     _monitorexit_slowcase_cnt++;
 771   }
 772 #endif
 773   assert(current->last_Java_sp(), "last_Java_sp must be set");
 774   oop obj = lock->obj();
 775   assert(oopDesc::is_oop(obj), "must be NULL or an object");
 776   SharedRuntime::monitor_exit_helper(obj, lock->lock(), current);
 777 JRT_END
 778 
 779 // Cf. OptoRuntime::deoptimize_caller_frame
 780 JRT_ENTRY(void, Runtime1::deoptimize(JavaThread* current, jint trap_request))
 781   // Called from within the owner thread, so no need for safepoint
 782   RegisterMap reg_map(current,
 783                       RegisterMap::UpdateMap::skip,
 784                       RegisterMap::ProcessFrames::include,
 785                       RegisterMap::WalkContinuation::skip);
 786   frame stub_frame = current->last_frame();
 787   assert(stub_frame.is_runtime_frame(), "Sanity check");
 788   frame caller_frame = stub_frame.sender(&reg_map);
 789   nmethod* nm = caller_frame.cb()->as_nmethod_or_null();
 790   assert(nm != NULL, "Sanity check");
 791   methodHandle method(current, nm->method());
 792   assert(nm == CodeCache::find_nmethod(caller_frame.pc()), "Should be the same");
 793   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
 794   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
 795 
 796   if (action == Deoptimization::Action_make_not_entrant) {
 797     if (nm->make_not_entrant()) {
 798       if (reason == Deoptimization::Reason_tenured) {
 799         MethodData* trap_mdo = Deoptimization::get_method_data(current, method, true /*create_if_missing*/);
 800         if (trap_mdo != NULL) {
 801           trap_mdo->inc_tenure_traps();
 802         }
 803       }
 804     }
 805   }
 806 
 807   // Deoptimize the caller frame.
 808   Deoptimization::deoptimize_frame(current, caller_frame.id());
 809   // Return to the now deoptimized frame.
 810 JRT_END
 811 
 812 
 813 #ifndef DEOPTIMIZE_WHEN_PATCHING
 814 
 815 static Klass* resolve_field_return_klass(const methodHandle& caller, int bci, TRAPS) {
 816   Bytecode_field field_access(caller, bci);
 817   // This can be static or non-static field access
 818   Bytecodes::Code code       = field_access.code();
 819 
 820   // We must load class, initialize class and resolve the field
 821   fieldDescriptor result; // initialize class if needed
 822   constantPoolHandle constants(THREAD, caller->constants());
 823   LinkResolver::resolve_field_access(result, constants, field_access.index(), caller, Bytecodes::java_code(code), CHECK_NULL);
 824   return result.field_holder();
 825 }
 826 
 827 
 828 //
 829 // This routine patches sites where a class wasn't loaded or
 830 // initialized at the time the code was generated.  It handles
 831 // references to classes, fields and forcing of initialization.  Most
 832 // of the cases are straightforward and involving simply forcing
 833 // resolution of a class, rewriting the instruction stream with the
 834 // needed constant and replacing the call in this function with the
 835 // patched code.  The case for static field is more complicated since
 836 // the thread which is in the process of initializing a class can
 837 // access it's static fields but other threads can't so the code
 838 // either has to deoptimize when this case is detected or execute a
 839 // check that the current thread is the initializing thread.  The
 840 // current
 841 //
 842 // Patches basically look like this:
 843 //
 844 //
 845 // patch_site: jmp patch stub     ;; will be patched
 846 // continue:   ...
 847 //             ...
 848 //             ...
 849 //             ...
 850 //
 851 // They have a stub which looks like this:
 852 //
 853 //             ;; patch body
 854 //             movl <const>, reg           (for class constants)
 855 //        <or> movl [reg1 + <const>], reg  (for field offsets)
 856 //        <or> movl reg, [reg1 + <const>]  (for field offsets)
 857 //             <being_init offset> <bytes to copy> <bytes to skip>
 858 // patch_stub: call Runtime1::patch_code (through a runtime stub)
 859 //             jmp patch_site
 860 //
 861 //
 862 // A normal patch is done by rewriting the patch body, usually a move,
 863 // and then copying it into place over top of the jmp instruction
 864 // being careful to flush caches and doing it in an MP-safe way.  The
 865 // constants following the patch body are used to find various pieces
 866 // of the patch relative to the call site for Runtime1::patch_code.
 867 // The case for getstatic and putstatic is more complicated because
 868 // getstatic and putstatic have special semantics when executing while
 869 // the class is being initialized.  getstatic/putstatic on a class
 870 // which is being_initialized may be executed by the initializing
 871 // thread but other threads have to block when they execute it.  This
 872 // is accomplished in compiled code by executing a test of the current
 873 // thread against the initializing thread of the class.  It's emitted
 874 // as boilerplate in their stub which allows the patched code to be
 875 // executed before it's copied back into the main body of the nmethod.
 876 //
 877 // being_init: get_thread(<tmp reg>
 878 //             cmpl [reg1 + <init_thread_offset>], <tmp reg>
 879 //             jne patch_stub
 880 //             movl [reg1 + <const>], reg  (for field offsets)  <or>
 881 //             movl reg, [reg1 + <const>]  (for field offsets)
 882 //             jmp continue
 883 //             <being_init offset> <bytes to copy> <bytes to skip>
 884 // patch_stub: jmp Runtim1::patch_code (through a runtime stub)
 885 //             jmp patch_site
 886 //
 887 // If the class is being initialized the patch body is rewritten and
 888 // the patch site is rewritten to jump to being_init, instead of
 889 // patch_stub.  Whenever this code is executed it checks the current
 890 // thread against the initializing thread so other threads will enter
 891 // the runtime and end up blocked waiting the class to finish
 892 // initializing inside the calls to resolve_field below.  The
 893 // initializing class will continue on it's way.  Once the class is
 894 // fully_initialized, the intializing_thread of the class becomes
 895 // NULL, so the next thread to execute this code will fail the test,
 896 // call into patch_code and complete the patching process by copying
 897 // the patch body back into the main part of the nmethod and resume
 898 // executing.
 899 
 900 // NB:
 901 //
 902 // Patchable instruction sequences inherently exhibit race conditions,
 903 // where thread A is patching an instruction at the same time thread B
 904 // is executing it.  The algorithms we use ensure that any observation
 905 // that B can make on any intermediate states during A's patching will
 906 // always end up with a correct outcome.  This is easiest if there are
 907 // few or no intermediate states.  (Some inline caches have two
 908 // related instructions that must be patched in tandem.  For those,
 909 // intermediate states seem to be unavoidable, but we will get the
 910 // right answer from all possible observation orders.)
 911 //
 912 // When patching the entry instruction at the head of a method, or a
 913 // linkable call instruction inside of a method, we try very hard to
 914 // use a patch sequence which executes as a single memory transaction.
 915 // This means, in practice, that when thread A patches an instruction,
 916 // it should patch a 32-bit or 64-bit word that somehow overlaps the
 917 // instruction or is contained in it.  We believe that memory hardware
 918 // will never break up such a word write, if it is naturally aligned
 919 // for the word being written.  We also know that some CPUs work very
 920 // hard to create atomic updates even of naturally unaligned words,
 921 // but we don't want to bet the farm on this always working.
 922 //
 923 // Therefore, if there is any chance of a race condition, we try to
 924 // patch only naturally aligned words, as single, full-word writes.
 925 
 926 JRT_ENTRY(void, Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id ))
 927 #ifndef PRODUCT
 928   if (PrintC1Statistics) {
 929     _patch_code_slowcase_cnt++;
 930   }
 931 #endif
 932 
 933   ResourceMark rm(current);
 934   RegisterMap reg_map(current,
 935                       RegisterMap::UpdateMap::skip,
 936                       RegisterMap::ProcessFrames::include,
 937                       RegisterMap::WalkContinuation::skip);
 938   frame runtime_frame = current->last_frame();
 939   frame caller_frame = runtime_frame.sender(&reg_map);
 940 
 941   // last java frame on stack
 942   vframeStream vfst(current, true);
 943   assert(!vfst.at_end(), "Java frame must exist");
 944 
 945   methodHandle caller_method(current, vfst.method());
 946   // Note that caller_method->code() may not be same as caller_code because of OSR's
 947   // Note also that in the presence of inlining it is not guaranteed
 948   // that caller_method() == caller_code->method()
 949 
 950   int bci = vfst.bci();
 951   Bytecodes::Code code = caller_method()->java_code_at(bci);
 952 
 953   // this is used by assertions in the access_field_patching_id
 954   BasicType patch_field_type = T_ILLEGAL;
 955   bool deoptimize_for_volatile = false;
 956   bool deoptimize_for_atomic = false;
 957   int patch_field_offset = -1;
 958   Klass* init_klass = NULL; // klass needed by load_klass_patching code
 959   Klass* load_klass = NULL; // klass needed by load_klass_patching code
 960   Handle mirror(current, NULL);                    // oop needed by load_mirror_patching code
 961   Handle appendix(current, NULL);                  // oop needed by appendix_patching code
 962   bool load_klass_or_mirror_patch_id =
 963     (stub_id == Runtime1::load_klass_patching_id || stub_id == Runtime1::load_mirror_patching_id);
 964 
 965   if (stub_id == Runtime1::access_field_patching_id) {
 966 
 967     Bytecode_field field_access(caller_method, bci);
 968     fieldDescriptor result; // initialize class if needed
 969     Bytecodes::Code code = field_access.code();
 970     constantPoolHandle constants(current, caller_method->constants());
 971     LinkResolver::resolve_field_access(result, constants, field_access.index(), caller_method, Bytecodes::java_code(code), CHECK);
 972     patch_field_offset = result.offset();
 973 
 974     // If we're patching a field which is volatile then at compile it
 975     // must not have been know to be volatile, so the generated code
 976     // isn't correct for a volatile reference.  The nmethod has to be
 977     // deoptimized so that the code can be regenerated correctly.
 978     // This check is only needed for access_field_patching since this
 979     // is the path for patching field offsets.  load_klass is only
 980     // used for patching references to oops which don't need special
 981     // handling in the volatile case.
 982 
 983     deoptimize_for_volatile = result.access_flags().is_volatile();
 984 
 985     // If we are patching a field which should be atomic, then
 986     // the generated code is not correct either, force deoptimizing.
 987     // We need to only cover T_LONG and T_DOUBLE fields, as we can
 988     // break access atomicity only for them.
 989 
 990     // Strictly speaking, the deoptimization on 64-bit platforms
 991     // is unnecessary, and T_LONG stores on 32-bit platforms need
 992     // to be handled by special patching code when AlwaysAtomicAccesses
 993     // becomes product feature. At this point, we are still going
 994     // for the deoptimization for consistency against volatile
 995     // accesses.
 996 
 997     patch_field_type = result.field_type();
 998     deoptimize_for_atomic = (AlwaysAtomicAccesses && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG));
 999 
1000   } else if (load_klass_or_mirror_patch_id) {
1001     Klass* k = NULL;
1002     switch (code) {
1003       case Bytecodes::_putstatic:
1004       case Bytecodes::_getstatic:
1005         { Klass* klass = resolve_field_return_klass(caller_method, bci, CHECK);
1006           init_klass = klass;
1007           mirror = Handle(current, klass->java_mirror());
1008         }
1009         break;
1010       case Bytecodes::_new:
1011         { Bytecode_new bnew(caller_method(), caller_method->bcp_from(bci));
1012           k = caller_method->constants()->klass_at(bnew.index(), CHECK);
1013         }
1014         break;
1015       case Bytecodes::_multianewarray:
1016         { Bytecode_multianewarray mna(caller_method(), caller_method->bcp_from(bci));
1017           k = caller_method->constants()->klass_at(mna.index(), CHECK);
1018         }
1019         break;
1020       case Bytecodes::_instanceof:
1021         { Bytecode_instanceof io(caller_method(), caller_method->bcp_from(bci));
1022           k = caller_method->constants()->klass_at(io.index(), CHECK);
1023         }
1024         break;
1025       case Bytecodes::_checkcast:
1026         { Bytecode_checkcast cc(caller_method(), caller_method->bcp_from(bci));
1027           k = caller_method->constants()->klass_at(cc.index(), CHECK);
1028         }
1029         break;
1030       case Bytecodes::_anewarray:
1031         { Bytecode_anewarray anew(caller_method(), caller_method->bcp_from(bci));
1032           Klass* ek = caller_method->constants()->klass_at(anew.index(), CHECK);
1033           k = ek->array_klass(CHECK);
1034         }
1035         break;
1036       case Bytecodes::_ldc:
1037       case Bytecodes::_ldc_w:
1038       case Bytecodes::_ldc2_w:
1039         {
1040           Bytecode_loadconstant cc(caller_method, bci);
1041           oop m = cc.resolve_constant(CHECK);
1042           mirror = Handle(current, m);
1043         }
1044         break;
1045       default: fatal("unexpected bytecode for load_klass_or_mirror_patch_id");
1046     }
1047     load_klass = k;
1048   } else if (stub_id == load_appendix_patching_id) {
1049     Bytecode_invoke bytecode(caller_method, bci);
1050     Bytecodes::Code bc = bytecode.invoke_code();
1051 
1052     CallInfo info;
1053     constantPoolHandle pool(current, caller_method->constants());
1054     int index = bytecode.index();
1055     LinkResolver::resolve_invoke(info, Handle(), pool, index, bc, CHECK);
1056     switch (bc) {
1057       case Bytecodes::_invokehandle: {
1058         int cache_index = ConstantPool::decode_cpcache_index(index, true);
1059         assert(cache_index >= 0 && cache_index < pool->cache()->length(), "unexpected cache index");
1060         ConstantPoolCacheEntry* cpce = pool->cache()->entry_at(cache_index);
1061         cpce->set_method_handle(pool, info);
1062         appendix = Handle(current, cpce->appendix_if_resolved(pool)); // just in case somebody already resolved the entry
1063         break;
1064       }
1065       case Bytecodes::_invokedynamic: {
1066         ConstantPoolCacheEntry* cpce = pool->invokedynamic_cp_cache_entry_at(index);
1067         cpce->set_dynamic_call(pool, info);
1068         appendix = Handle(current, cpce->appendix_if_resolved(pool)); // just in case somebody already resolved the entry
1069         break;
1070       }
1071       default: fatal("unexpected bytecode for load_appendix_patching_id");
1072     }
1073   } else {
1074     ShouldNotReachHere();
1075   }
1076 
1077   if (deoptimize_for_volatile || deoptimize_for_atomic) {
1078     // At compile time we assumed the field wasn't volatile/atomic but after
1079     // loading it turns out it was volatile/atomic so we have to throw the
1080     // compiled code out and let it be regenerated.
1081     if (TracePatching) {
1082       if (deoptimize_for_volatile) {
1083         tty->print_cr("Deoptimizing for patching volatile field reference");
1084       }
1085       if (deoptimize_for_atomic) {
1086         tty->print_cr("Deoptimizing for patching atomic field reference");
1087       }
1088     }
1089 
1090     // It's possible the nmethod was invalidated in the last
1091     // safepoint, but if it's still alive then make it not_entrant.
1092     nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1093     if (nm != NULL) {
1094       nm->make_not_entrant();
1095     }
1096 
1097     Deoptimization::deoptimize_frame(current, caller_frame.id());
1098 
1099     // Return to the now deoptimized frame.
1100   }
1101 
1102   // Now copy code back
1103 
1104   {
1105     MutexLocker ml_patch (current, Patching_lock, Mutex::_no_safepoint_check_flag);
1106     //
1107     // Deoptimization may have happened while we waited for the lock.
1108     // In that case we don't bother to do any patching we just return
1109     // and let the deopt happen
1110     if (!caller_is_deopted(current)) {
1111       NativeGeneralJump* jump = nativeGeneralJump_at(caller_frame.pc());
1112       address instr_pc = jump->jump_destination();
1113       NativeInstruction* ni = nativeInstruction_at(instr_pc);
1114       if (ni->is_jump() ) {
1115         // the jump has not been patched yet
1116         // The jump destination is slow case and therefore not part of the stubs
1117         // (stubs are only for StaticCalls)
1118 
1119         // format of buffer
1120         //    ....
1121         //    instr byte 0     <-- copy_buff
1122         //    instr byte 1
1123         //    ..
1124         //    instr byte n-1
1125         //      n
1126         //    ....             <-- call destination
1127 
1128         address stub_location = caller_frame.pc() + PatchingStub::patch_info_offset();
1129         unsigned char* byte_count = (unsigned char*) (stub_location - 1);
1130         unsigned char* byte_skip = (unsigned char*) (stub_location - 2);
1131         unsigned char* being_initialized_entry_offset = (unsigned char*) (stub_location - 3);
1132         address copy_buff = stub_location - *byte_skip - *byte_count;
1133         address being_initialized_entry = stub_location - *being_initialized_entry_offset;
1134         if (TracePatching) {
1135           ttyLocker ttyl;
1136           tty->print_cr(" Patching %s at bci %d at address " INTPTR_FORMAT "  (%s)", Bytecodes::name(code), bci,
1137                         p2i(instr_pc), (stub_id == Runtime1::access_field_patching_id) ? "field" : "klass");
1138           nmethod* caller_code = CodeCache::find_nmethod(caller_frame.pc());
1139           assert(caller_code != NULL, "nmethod not found");
1140 
1141           // NOTE we use pc() not original_pc() because we already know they are
1142           // identical otherwise we'd have never entered this block of code
1143 
1144           const ImmutableOopMap* map = caller_code->oop_map_for_return_address(caller_frame.pc());
1145           assert(map != NULL, "null check");
1146           map->print();
1147           tty->cr();
1148 
1149           Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1150         }
1151         // depending on the code below, do_patch says whether to copy the patch body back into the nmethod
1152         bool do_patch = true;
1153         if (stub_id == Runtime1::access_field_patching_id) {
1154           // The offset may not be correct if the class was not loaded at code generation time.
1155           // Set it now.
1156           NativeMovRegMem* n_move = nativeMovRegMem_at(copy_buff);
1157           assert(n_move->offset() == 0 || (n_move->offset() == 4 && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG)), "illegal offset for type");
1158           assert(patch_field_offset >= 0, "illegal offset");
1159           n_move->add_offset_in_bytes(patch_field_offset);
1160         } else if (load_klass_or_mirror_patch_id) {
1161           // If a getstatic or putstatic is referencing a klass which
1162           // isn't fully initialized, the patch body isn't copied into
1163           // place until initialization is complete.  In this case the
1164           // patch site is setup so that any threads besides the
1165           // initializing thread are forced to come into the VM and
1166           // block.
1167           do_patch = (code != Bytecodes::_getstatic && code != Bytecodes::_putstatic) ||
1168                      InstanceKlass::cast(init_klass)->is_initialized();
1169           NativeGeneralJump* jump = nativeGeneralJump_at(instr_pc);
1170           if (jump->jump_destination() == being_initialized_entry) {
1171             assert(do_patch == true, "initialization must be complete at this point");
1172           } else {
1173             // patch the instruction <move reg, klass>
1174             NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1175 
1176             assert(n_copy->data() == 0 ||
1177                    n_copy->data() == (intptr_t)Universe::non_oop_word(),
1178                    "illegal init value");
1179             if (stub_id == Runtime1::load_klass_patching_id) {
1180               assert(load_klass != NULL, "klass not set");
1181               n_copy->set_data((intx) (load_klass));
1182             } else {
1183               // Don't need a G1 pre-barrier here since we assert above that data isn't an oop.
1184               n_copy->set_data(cast_from_oop<intx>(mirror()));
1185             }
1186 
1187             if (TracePatching) {
1188               Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1189             }
1190           }
1191         } else if (stub_id == Runtime1::load_appendix_patching_id) {
1192           NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1193           assert(n_copy->data() == 0 ||
1194                  n_copy->data() == (intptr_t)Universe::non_oop_word(),
1195                  "illegal init value");
1196           n_copy->set_data(cast_from_oop<intx>(appendix()));
1197 
1198           if (TracePatching) {
1199             Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1200           }
1201         } else {
1202           ShouldNotReachHere();
1203         }
1204 
1205         if (do_patch) {
1206           // replace instructions
1207           // first replace the tail, then the call
1208 #ifdef ARM
1209           if((load_klass_or_mirror_patch_id ||
1210               stub_id == Runtime1::load_appendix_patching_id) &&
1211               nativeMovConstReg_at(copy_buff)->is_pc_relative()) {
1212             nmethod* nm = CodeCache::find_nmethod(instr_pc);
1213             address addr = NULL;
1214             assert(nm != NULL, "invalid nmethod_pc");
1215             RelocIterator mds(nm, copy_buff, copy_buff + 1);
1216             while (mds.next()) {
1217               if (mds.type() == relocInfo::oop_type) {
1218                 assert(stub_id == Runtime1::load_mirror_patching_id ||
1219                        stub_id == Runtime1::load_appendix_patching_id, "wrong stub id");
1220                 oop_Relocation* r = mds.oop_reloc();
1221                 addr = (address)r->oop_addr();
1222                 break;
1223               } else if (mds.type() == relocInfo::metadata_type) {
1224                 assert(stub_id == Runtime1::load_klass_patching_id, "wrong stub id");
1225                 metadata_Relocation* r = mds.metadata_reloc();
1226                 addr = (address)r->metadata_addr();
1227                 break;
1228               }
1229             }
1230             assert(addr != NULL, "metadata relocation must exist");
1231             copy_buff -= *byte_count;
1232             NativeMovConstReg* n_copy2 = nativeMovConstReg_at(copy_buff);
1233             n_copy2->set_pc_relative_offset(addr, instr_pc);
1234           }
1235 #endif
1236 
1237           for (int i = NativeGeneralJump::instruction_size; i < *byte_count; i++) {
1238             address ptr = copy_buff + i;
1239             int a_byte = (*ptr) & 0xFF;
1240             address dst = instr_pc + i;
1241             *(unsigned char*)dst = (unsigned char) a_byte;
1242           }
1243           ICache::invalidate_range(instr_pc, *byte_count);
1244           NativeGeneralJump::replace_mt_safe(instr_pc, copy_buff);
1245 
1246           if (load_klass_or_mirror_patch_id ||
1247               stub_id == Runtime1::load_appendix_patching_id) {
1248             relocInfo::relocType rtype =
1249               (stub_id == Runtime1::load_klass_patching_id) ?
1250                                    relocInfo::metadata_type :
1251                                    relocInfo::oop_type;
1252             // update relocInfo to metadata
1253             nmethod* nm = CodeCache::find_nmethod(instr_pc);
1254             assert(nm != NULL, "invalid nmethod_pc");
1255 
1256             // The old patch site is now a move instruction so update
1257             // the reloc info so that it will get updated during
1258             // future GCs.
1259             RelocIterator iter(nm, (address)instr_pc, (address)(instr_pc + 1));
1260             relocInfo::change_reloc_info_for_address(&iter, (address) instr_pc,
1261                                                      relocInfo::none, rtype);
1262           }
1263 
1264         } else {
1265           ICache::invalidate_range(copy_buff, *byte_count);
1266           NativeGeneralJump::insert_unconditional(instr_pc, being_initialized_entry);
1267         }
1268       }
1269     }
1270   }
1271 
1272   // If we are patching in a non-perm oop, make sure the nmethod
1273   // is on the right list.
1274   {
1275     MutexLocker ml_code (current, CodeCache_lock, Mutex::_no_safepoint_check_flag);
1276     nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1277     guarantee(nm != NULL, "only nmethods can contain non-perm oops");
1278 
1279     // Since we've patched some oops in the nmethod,
1280     // (re)register it with the heap.
1281     Universe::heap()->register_nmethod(nm);
1282   }
1283 JRT_END
1284 
1285 #else // DEOPTIMIZE_WHEN_PATCHING
1286 
1287 void Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id) {
1288 #ifndef PRODUCT
1289   if (PrintC1Statistics) {
1290     _patch_code_slowcase_cnt++;
1291   }
1292 #endif
1293 
1294   // Enable WXWrite: the function is called by c1 stub as a runtime function
1295   // (see another implementation above).
1296   MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
1297 
1298   if (TracePatching) {
1299     tty->print_cr("Deoptimizing because patch is needed");
1300   }
1301 
1302   RegisterMap reg_map(current,
1303                       RegisterMap::UpdateMap::skip,
1304                       RegisterMap::ProcessFrames::include,
1305                       RegisterMap::WalkContinuation::skip);
1306 
1307   frame runtime_frame = current->last_frame();
1308   frame caller_frame = runtime_frame.sender(&reg_map);
1309   assert(caller_frame.is_compiled_frame(), "Wrong frame type");
1310 
1311   // Make sure the nmethod is invalidated, i.e. made not entrant.
1312   nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1313   if (nm != NULL) {
1314     nm->make_not_entrant();
1315   }
1316 
1317   Deoptimization::deoptimize_frame(current, caller_frame.id());
1318   // Return to the now deoptimized frame.
1319   postcond(caller_is_deopted(current));
1320 }
1321 
1322 #endif // DEOPTIMIZE_WHEN_PATCHING
1323 
1324 // Entry point for compiled code. We want to patch a nmethod.
1325 // We don't do a normal VM transition here because we want to
1326 // know after the patching is complete and any safepoint(s) are taken
1327 // if the calling nmethod was deoptimized. We do this by calling a
1328 // helper method which does the normal VM transition and when it
1329 // completes we can check for deoptimization. This simplifies the
1330 // assembly code in the cpu directories.
1331 //
1332 int Runtime1::move_klass_patching(JavaThread* current) {
1333 //
1334 // NOTE: we are still in Java
1335 //
1336   debug_only(NoHandleMark nhm;)
1337   {
1338     // Enter VM mode
1339     ResetNoHandleMark rnhm;
1340     patch_code(current, load_klass_patching_id);
1341   }
1342   // Back in JAVA, use no oops DON'T safepoint
1343 
1344   // Return true if calling code is deoptimized
1345 
1346   return caller_is_deopted(current);
1347 }
1348 
1349 int Runtime1::move_mirror_patching(JavaThread* current) {
1350 //
1351 // NOTE: we are still in Java
1352 //
1353   debug_only(NoHandleMark nhm;)
1354   {
1355     // Enter VM mode
1356     ResetNoHandleMark rnhm;
1357     patch_code(current, load_mirror_patching_id);
1358   }
1359   // Back in JAVA, use no oops DON'T safepoint
1360 
1361   // Return true if calling code is deoptimized
1362 
1363   return caller_is_deopted(current);
1364 }
1365 
1366 int Runtime1::move_appendix_patching(JavaThread* current) {
1367 //
1368 // NOTE: we are still in Java
1369 //
1370   debug_only(NoHandleMark nhm;)
1371   {
1372     // Enter VM mode
1373     ResetNoHandleMark rnhm;
1374     patch_code(current, load_appendix_patching_id);
1375   }
1376   // Back in JAVA, use no oops DON'T safepoint
1377 
1378   // Return true if calling code is deoptimized
1379 
1380   return caller_is_deopted(current);
1381 }
1382 
1383 // Entry point for compiled code. We want to patch a nmethod.
1384 // We don't do a normal VM transition here because we want to
1385 // know after the patching is complete and any safepoint(s) are taken
1386 // if the calling nmethod was deoptimized. We do this by calling a
1387 // helper method which does the normal VM transition and when it
1388 // completes we can check for deoptimization. This simplifies the
1389 // assembly code in the cpu directories.
1390 //
1391 int Runtime1::access_field_patching(JavaThread* current) {
1392   //
1393   // NOTE: we are still in Java
1394   //
1395   // Handles created in this function will be deleted by the
1396   // HandleMarkCleaner in the transition to the VM.
1397   NoHandleMark nhm;
1398   {
1399     // Enter VM mode
1400     ResetNoHandleMark rnhm;
1401     patch_code(current, access_field_patching_id);
1402   }
1403   // Back in JAVA, use no oops DON'T safepoint
1404 
1405   // Return true if calling code is deoptimized
1406 
1407   return caller_is_deopted(current);
1408 }
1409 
1410 
1411 JRT_LEAF(void, Runtime1::trace_block_entry(jint block_id))
1412   // for now we just print out the block id
1413   tty->print("%d ", block_id);
1414 JRT_END
1415 
1416 
1417 JRT_LEAF(int, Runtime1::is_instance_of(oopDesc* mirror, oopDesc* obj))
1418   // had to return int instead of bool, otherwise there may be a mismatch
1419   // between the C calling convention and the Java one.
1420   // e.g., on x86, GCC may clear only %al when returning a bool false, but
1421   // JVM takes the whole %eax as the return value, which may misinterpret
1422   // the return value as a boolean true.
1423 
1424   assert(mirror != NULL, "should null-check on mirror before calling");
1425   Klass* k = java_lang_Class::as_Klass(mirror);
1426   return (k != NULL && obj != NULL && obj->is_a(k)) ? 1 : 0;
1427 JRT_END
1428 
1429 JRT_ENTRY(void, Runtime1::predicate_failed_trap(JavaThread* current))
1430   ResourceMark rm;
1431 
1432   RegisterMap reg_map(current,
1433                       RegisterMap::UpdateMap::skip,
1434                       RegisterMap::ProcessFrames::include,
1435                       RegisterMap::WalkContinuation::skip);
1436   frame runtime_frame = current->last_frame();
1437   frame caller_frame = runtime_frame.sender(&reg_map);
1438 
1439   nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1440   assert (nm != NULL, "no more nmethod?");
1441   nm->make_not_entrant();
1442 
1443   methodHandle m(current, nm->method());
1444   MethodData* mdo = m->method_data();
1445 
1446   if (mdo == NULL && !HAS_PENDING_EXCEPTION) {
1447     // Build an MDO.  Ignore errors like OutOfMemory;
1448     // that simply means we won't have an MDO to update.
1449     Method::build_profiling_method_data(m, THREAD);
1450     if (HAS_PENDING_EXCEPTION) {
1451       // Only metaspace OOM is expected. No Java code executed.
1452       assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1453       CLEAR_PENDING_EXCEPTION;
1454     }
1455     mdo = m->method_data();
1456   }
1457 
1458   if (mdo != NULL) {
1459     mdo->inc_trap_count(Deoptimization::Reason_none);
1460   }
1461 
1462   if (TracePredicateFailedTraps) {
1463     stringStream ss1, ss2;
1464     vframeStream vfst(current);
1465     Method* inlinee = vfst.method();
1466     inlinee->print_short_name(&ss1);
1467     m->print_short_name(&ss2);
1468     tty->print_cr("Predicate failed trap in method %s at bci %d inlined in %s at pc " INTPTR_FORMAT, ss1.as_string(), vfst.bci(), ss2.as_string(), p2i(caller_frame.pc()));
1469   }
1470 
1471 
1472   Deoptimization::deoptimize_frame(current, caller_frame.id());
1473 
1474 JRT_END
1475 
1476 #ifndef PRODUCT
1477 void Runtime1::print_statistics() {
1478   tty->print_cr("C1 Runtime statistics:");
1479   tty->print_cr(" _resolve_invoke_virtual_cnt:     %d", SharedRuntime::_resolve_virtual_ctr);
1480   tty->print_cr(" _resolve_invoke_opt_virtual_cnt: %d", SharedRuntime::_resolve_opt_virtual_ctr);
1481   tty->print_cr(" _resolve_invoke_static_cnt:      %d", SharedRuntime::_resolve_static_ctr);
1482   tty->print_cr(" _handle_wrong_method_cnt:        %d", SharedRuntime::_wrong_method_ctr);
1483   tty->print_cr(" _ic_miss_cnt:                    %d", SharedRuntime::_ic_miss_ctr);
1484   tty->print_cr(" _generic_arraycopystub_cnt:      %d", _generic_arraycopystub_cnt);
1485   tty->print_cr(" _byte_arraycopy_cnt:             %d", _byte_arraycopy_stub_cnt);
1486   tty->print_cr(" _short_arraycopy_cnt:            %d", _short_arraycopy_stub_cnt);
1487   tty->print_cr(" _int_arraycopy_cnt:              %d", _int_arraycopy_stub_cnt);
1488   tty->print_cr(" _long_arraycopy_cnt:             %d", _long_arraycopy_stub_cnt);
1489   tty->print_cr(" _oop_arraycopy_cnt:              %d", _oop_arraycopy_stub_cnt);
1490   tty->print_cr(" _arraycopy_slowcase_cnt:         %d", _arraycopy_slowcase_cnt);
1491   tty->print_cr(" _arraycopy_checkcast_cnt:        %d", _arraycopy_checkcast_cnt);
1492   tty->print_cr(" _arraycopy_checkcast_attempt_cnt:%d", _arraycopy_checkcast_attempt_cnt);
1493 
1494   tty->print_cr(" _new_type_array_slowcase_cnt:    %d", _new_type_array_slowcase_cnt);
1495   tty->print_cr(" _new_object_array_slowcase_cnt:  %d", _new_object_array_slowcase_cnt);
1496   tty->print_cr(" _new_instance_slowcase_cnt:      %d", _new_instance_slowcase_cnt);
1497   tty->print_cr(" _new_multi_array_slowcase_cnt:   %d", _new_multi_array_slowcase_cnt);
1498   tty->print_cr(" _monitorenter_slowcase_cnt:      %d", _monitorenter_slowcase_cnt);
1499   tty->print_cr(" _monitorexit_slowcase_cnt:       %d", _monitorexit_slowcase_cnt);
1500   tty->print_cr(" _patch_code_slowcase_cnt:        %d", _patch_code_slowcase_cnt);
1501 
1502   tty->print_cr(" _throw_range_check_exception_count:            %d:", _throw_range_check_exception_count);
1503   tty->print_cr(" _throw_index_exception_count:                  %d:", _throw_index_exception_count);
1504   tty->print_cr(" _throw_div0_exception_count:                   %d:", _throw_div0_exception_count);
1505   tty->print_cr(" _throw_null_pointer_exception_count:           %d:", _throw_null_pointer_exception_count);
1506   tty->print_cr(" _throw_class_cast_exception_count:             %d:", _throw_class_cast_exception_count);
1507   tty->print_cr(" _throw_incompatible_class_change_error_count:  %d:", _throw_incompatible_class_change_error_count);
1508   tty->print_cr(" _throw_count:                                  %d:", _throw_count);
1509 
1510   SharedRuntime::print_ic_miss_histogram();
1511   tty->cr();
1512 }
1513 #endif // PRODUCT
--- EOF ---